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This is a relatively rare but striking disease characterized by a diffuse papulosquamous rash with characteristic islands of sparing.


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Pityriasis rubra pilaris in black South Africans.

Jacyk WK.

Department of Dermatology, University of Pretoria, Republic of South Africa.

Clin Exp Dermatol 1999 May;24(3):160-3 Abstract quote

Eighteen black South African patients with pityriasis rubra pilaris were prospectively studied, nine adults and nine children; patients with the classical types (namely I and III) constituted 75% of the group. Follicular involvement was very prominent, especially in the children with type III, but otherwise the clinical and histological findings did not differ from those reported in white patients.

This is the first series of black African patients with this condition to be reported.



The relationship between pityriasis rubra pilaris and inflammatory arthritis: case report and response of the arthritis to anti-tumor necrosis factor immunotherapy.

Conaghan PG, Sommer S, McGonagle D, Veale D, Waldmann H, Hale G, Goodfield M, Emery P, Isaacs J.

University of Leeds, UK.

Arthritis Rheum 1999 Sep;42(9):1998-2001 Abstract quote

Pityriasis rubra pilaris (PRP) refers to a group of erythematous, scaling dermatologic conditions that have been associated with seronegative arthritis.

We report a case of polyarthritis in a young man with PRP in which magnetic resonance imaging suggested an entheseal-based pathology for the joint disease. The arthritis, but not the skin condition, demonstrated dramatic response to anti-tumor necrosis factor immunotherapy.

Atypical pityriasis rubra pilaris associated with arthropathy and osteoporosis: a case report with 15-year follow-up.

Behr FD, Bangert JL, Hansen RC.

Section of Dermatology, University of Arizona College of Medicine, Tucson, Arizona, USA.

Pediatr Dermatol 2002 Jan-Feb;19(1):46-51 Abstract quote

Pityriasis rubra pilaris (PRP) is an idiopathic papulosquamous disease that clinically presents with palmoplantar keratoderma and follicular hyperkeratotic papules that coalesce into scaly erythematous plaques.

We report a unique case of atypical PRP beginning at 1 year of age with associated severe arthropathy and osteoporosis. We further discuss the clinical and histopathologic aspects of PRP, its possible etiology, and other associated conditions.


Dermatomyositis with a pityriasis rubra pilaris-like eruption: a little-known distinctive cutaneous manifestation of dermatomyositis.

Requena L, Grilli R, Soriano L, Escalonilla P, Farina C, Martin L.

Department of Dermatology, Fundacion Jimenez Diaz, Universidad Autonoma, Madrid, Spain.

Br J Dermatol 1997 May;136(5):768-71 Abstract quote

A pityriasis rubra pilaris-like eruption has been described in patients with dermatomyositis. These patients showed generalized follicular hyperkeratosis and diffuse thickening of the palms and soles. Histopathological findings consisted of keratotic plugging of the follicular infundibulum and features of erector pili myositis.

We report on an 18-year-old woman with dermatomyositis. The diagnosis was established by characteristic enzymatic alterations, electromyographic pattern of myositis and the findings in a muscle biopsy, although the patient had no evidence of muscular weakness during a follow-up of 14 years. She developed an erythematosus and squamous eruption associated with diffuse palmoplantar keratoderma.

Histopathological features consisted of a papillomatous epidermis with spicules of compact eosinophilic hyperkeratosis over the tips of papillae that were not related to hair follicles. Pityriasis rubra pilaris-like eruption seems to be a characteristic although uncommon cutaneous manifestation in dermatomyositis.

An unusual presentation of dermatomyositis: the type Wong variant revisited.

Lupton JR, Figueroa P, Berberian BJ, Sulica VI.

The George Washington University Medical Center, 2311 M St. NW, Washington, DC 20037, USA.

J Am Acad Dermatol 2000 Nov;43(5 Pt 2):908-12 Abstract quote

We describe a 53-year-old white woman with dermatomyositis (DM) who had additional clinical findings of pityriasis rubra pilaris (type Wong dermatomyositis) with histopathologic features of both pityriasis rubra pilaris (PRP) and porokeratosis.

Type Wong dermatomyositis was originally described in 11 patients by Wong in 1969 and has been reported in 5 additional patients. This is a rarely described phenomenon in which patients with DM develop cutaneous hyperkeratotic lesions that resemble PRP and histologically show follicular hyperkeratosis and hair follicle destruction. Arrector pilorum muscles also show degenerative findings and myositis.

We believe that this is the first reported case of a patient with type Wong DM who also has clinical and histologic features suggestive of porokeratosis. This is important because of the association of adult-onset dermatomyositis with internal malignancy and the well-documented association of porokeratosis with immunosuppression. These clinical and histologic findings serve as markers for malignancy in patients with DM. These patients warrant a complete review of systems and investigation for age-appropriate neoplasms as well as close long-term follow-up by dermatologists to ensure that these cutaneous eruptions are not overlooked.


Pityriasis rubra pilaris as an initial presentation of hepatocellular carcinoma.

Sharma S, Weiss GR, Paulger B.

Division of Oncology, University of Texas Health Science Center at San Antonio, 78284-7884, USA.

Dermatology 1997;194(2):166-7 Abstract quote

Pityriasis rubra pilaris (PRP) is a rare skin condition that is of unknown etiology.

We present an unusual case of a patient with PRP as the sole initial manifestation of hepatocellular cancer. The course of the patient's illness and management of this case is discussed. Possible reasons for this association are presented.

Pityriasis rubra pilaris and human immunodeficiency virus infection.

Miralles ES, Nunez M, De Las Heras ME, Perez B, Moreno R, Ledo A.

Servicio de Dermatologia Unisversidad Alcala de Henares, Hospital Ramon y Cajal, Madrid, Spain.

Br J Dermatol 1995 Dec;133(6):990-3 Abstract quote

Recently, the occurrence of pityriasis rubra pilaris (PRP) has been reported in patients with HIV infection. It presents different clinical features, and has a poorer prognosis, than the classical adult type of PRP.

We report the occurrence of severe PRP in an HIV-infected patient, and review the previously reported cases of this association. We propose the designation of a new category of PRP (type 6), characterized by the presence of HIV infection, usually without immunosuppression, a poor prognosis and response to treatment, and the development of nodulocystic and lichen spinulosus lesions.

Pityriasis rubra pilaris: an unusual cutaneous complication of AIDS.

Bonomo RA, Korman N, Nagashima-Whalen L, Briggs J, Graham R, Salata RA.

Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA

Am J Med Sci 1997 Aug;314(2):118-21 Abstract quote

Pityriasis rubra pilaris is an uncommon hyperkeratotic, papulosquamous disorder that has been reported in patients infected by HIV.

We recount a case of pityriasis rubra pilaris in an HIV-seropositive man. A 36-year-old man with a history of ulcerative colitis and recurrent otitis externa had diffuse psoriaform erythroderma. He was treated initially with methotrexate and isoretinoin without clinical improvement. Skin examination showed large, erythematous, orange, scaly patches on the upper extremities and thickening of the nail beds. The palms and soles were hyperkeratotic. Skin biopsy revealed changes that were consistent with pityriasis rubra pilaris. Six months before the onset of symptoms, results of an enzyme-linked immunosorbent assay (ELISA) and Western Blot assay for HIV were negative. Six months after symptoms, results of repeat enzyme-linked immunosorbent assay and Western blots for HIV were positive (CD4+ T-cell count = 200 cells/ mm3). Clinical course had been complicated by episodes of Staphylococcus aureus bacteremia, mucocutaneous candidiasis, and development of localized squamous cell carcinoma of the skin.

The increased severity of pityriasis rubra pilaris should prompt clinicians to consider coinfection with HIV in patients who have disease that is refractory to treatment. Clinicians also should remain vigilant for the development of squamous cell carcinoma.

HIV-associated pityriasis rubra pilaris responsive to triple antiretroviral therapy.

Gonzalez-Lopez A, Velasco E, Pozo T, Del Villar A.

Departments of Dermatology, Rio Hortega University Hospital, Valladolid, Spain.

Br J Dermatol 1999 May;140(5):931-4 Abstract quote

HIV-associated pityriasis rubra pilaris (PRP) or PRP type VI designates a new distinctive entity reported in HIV patients. It is characterized by cutaneous lesions of PRP and variable association with lesions of acne conglobata, hidradenitis suppurativa and lichen spinulosus.

We report a patient with HIV-associated PRP which was treated by triple antiretroviral therapy (zidovudine, lamivudin and saquinavir) with complete response. The patient has remained free from symptoms for 20 months of follow-up. We review the clinical features, pathology, evolution, treatment and possible aetiology of this recently described entity.


Merkel cell carcinoma and multiple cutaneous squamous cell carcinomas in a patient with pityriasis rubra pilaris.

Huynh NT, Hunt MJ, Cachia AR, Veness MJ.

Department of Dermatology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, New South Wales, Australia.

Australas J Dermatol 2002 Feb;43(1):48-51 Abstract quote

A 79-year-old female was diagnosed with Merkel cell carcinoma (MCC) and multiple cutaneous squamous cell carcinomas (SCC) occurring on a background of pityriasis rubra pilaris.

At the time of initial diagnosis and treatment for upper limb MCC, axillary nodal metastases were clinically evident. In the ensuing months, she developed multiple rapidly progressing SCC and eventually a left arm soft tissue deposit of metastatic MCC. Treatment involved multiple courses of fractionated radiotherapy.

The salient clinical features and supporting evidence for this case are presented.



Pityriasis rubra pilaris and and retinol-binding protein.

Finzi AF, Altomare G, Bergamaschini L, Tucci A.

Br J Dermatol 1981 Mar;104(3):253-6 Abstract quote

Serum levels of retinol-binding protein (the specific carrier of vitamin A) were measured in eleven patients with pityriasis rubra pilaris and in some of their close relatives.

The level of retinol-binding protein was markedly reduced in every patient, and in some of the relatives. It is postulated that defective synthesis of retinol-binding protein is a biochemical marker for pityriasis rubra pilaris, probably transmitted as a Mendelian dominant.


Pityriasis rubra pilaris: a new proposed classification.

Piamphongsant T, Akaraphant R.

Institute of Dermatology, Bangkok, Thailand.

Clin Exp Dermatol 1994 Mar;19(2):134-8 Abstract quote

Clinical features of pityriasis rubra pilaris (PRP) were classified into four types based on a study of 168 cases. All patients, except one case of type IV, and 12 cases of type II, have salmon-coloured or erythematous thick plaques on the palms and soles, which extended beyond the dorsopalmar and plantar junctions.

Twenty-one children and 11 adults presenting with such plaques were classified as type I PRP. Fifty-nine children and 27 adults presenting with circumscribed scaly erythematous patches on the elbows and knees were classified as type II. Twenty children and 16 adults with similar patches involving large areas of the trunk which were not generalized were classified as type III. Four children and 10 adults with exfoliative erythroderma associated with diffuse follicular plugging were classified as type IV. The diagnosis was confirmed by histopathology which showed follicular plugging and focal parakeratosis. However, this was not seen in type I.

This new clinical classification facilitates recognition of this type of PRP despite the absence of follicular plugging. Two children, initially classified as type I, showed gradual progression to type II on follow-up, with two adults progressing to type III, and 1 adult to type IV. Similarly, two adults classified as type II, progressed to type III, and 1 adult into type IV. Associated findings were an adult of type II who developed localized pustular psoriasis and another adult who developed ovarian adenocarcinoma.

Pityriasis rubra pilaris (PRP): report of four cases.

Sehgal VN, Bajaj P, Jain S.

Department of Pathology, Lady Hardinge Medical College, New Delhi, India.

J Dermatol 2000 Mar;27(3):174-7 Abstract quote

Four patients with pityriasis rubra pilaris are reported. The diagnosis in each was based upon well-recognized clinical features. Two of them, a mother and son, had the disease since childhood and were marked by relative remission in spring and exacerbation in autumn. Moderate to severe pruritus was a common dominator.

Erythroderma was a presenting feature in one case. Although histopathology was considered imperative, it only supplemented the clinical expression. Vitamin A in heavy dosage, supplemented by vitamin E and stanozolol in tandem, was the mainstay of treatment.


Childhood-onset pityriasis rubra pilaris with immunologic abnormalities.

Shvili D, David M, Mimouni M.

Pediatr Dermatol 1987 May;4(1):21-3 Abstract quote

We examined a 6-year-old boy with seborrheic dermatitis like redness of the face, scaling of the scalp, and palmoplantar keratoderma.

Skin biopsy showed hyperkeratosis, parakeratosis, follicular plugging, and mild upper dermal perifollicular mononuclear inflammatory infiltrate, which are compatible with the diagnosis of pityriasis rubra pilaris. Immunologic studies revealed normal values of peripheral B and T lymphocytes.

The spontaneous activity of T suppressor cells was activated and the function of T helper cells was impaired, however.

Juvenile pityriasis rubra pilaris associated with hypogammaglobulinaemia and furunculosis.

Castanet J, Lacour JP, Perrin C, Brun P, Ortonne JP.

Department of Dermatology, University of Nice, France.

Br J Dermatol 1994 Nov;131(5):717-9 Abstract quote

We report a case of follicular keratosis with inflammatory changes, consistent with a diagnosis of atypical juvenile pityriasis rubra pilaris.

An unusual feature was the occurrence of severe Staphylococcus aureus folliculitis and furunculosis, a phenomenon rarely encountered in pityriasis rubra pilaris and the other follicular keratoses. Standard antibiotic and antiseptic treatment for chronic S. aureus infection was ineffective.

The patient was subsequently found to have hypogammaglobulinaemia, and treatment with human polyvalent immunoglobulin infusions was successful in eradicating the sepsis. It is therefore probable that the hypogammaglobulinaemia played a pathogenic role in the development of cutaneous sepsis.

Acute juvenile pityriasis rubra pilaris: a superantigen mediated disease?

Betlloch I, Ramon R, Silvestre JF, Carnero L, Albares MP, Banuls J.

Department of Dermatology, General Universitary Hospital, Alicante, Spain.

Pediatr Dermatol 2001 Sep-Oct;18(5):411-4 Abstract quote

Juvenile acute pityriasis rubra pilaris (JAPRP) is a form of pityriasis rubra pilaris (PRP) with particular clinical characteristics and course. It is usually preceded by an infectious condition.

We report a boy, initially thought to have Kawasaki disease, and subsequently diagnosed as having JAPRP, who made a satisfactory recovery. In this case, prior antibiotic treatment made it impossible to show the presence of any microorganism. However, the clinical characteristics of these patients and the similarities with other disorders involving the skin that are mediated by superantigens led us to think that these antigens may be involved in the development of this disease. Also, in view of the obvious differences between JAPRP and the other PRP, we suggest that, in the future this disorder may be considered a separate entity as a reactive exanthem.

A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men.

Olsen EA, Dunlap FE, Funicella T, Koperski JA, Swinehart JM, Tschen EH, Trancik RJ.

Duke Dermatopharmacology Study Center, Durham, North Carolina, USA.

J Am Acad Dermatol 2002 Sep;47(3):377-85 Abstract quote

BACKGROUND: Topical minoxidil solution 2% stimulates new hair growth and helps stop the loss of hair in individuals with androgenetic alopecia (AGA). Results can be variable, and historical experience suggests that higher concentrations of topical minoxidil may enhance efficacy.

OBJECTIVE: The purpose of this 48-week, double-blind, placebo-controlled, randomized, multicenter trial was to compare 5% topical minoxidil with 2% topical minoxidil and placebo in the treatment of men with AGA.

METHODS: A total of 393 men (18-49 years old) with AGA applied 5% topical minoxidil solution (n = 157), 2% topical minoxidil solution (n = 158), or placebo (vehicle for 5% solution; n = 78) twice daily. Efficacy was evaluated by scalp target area hair counts and patient and investigator assessments of change in scalp coverage and benefit of treatment.

RESULTS: After 48 weeks of therapy, 5% topical minoxidil was significantly superior to 2% topical minoxidil and placebo in terms of change from baseline in nonvellus hair count, patient rating of scalp coverage and treatment benefit, and investigator rating of scalp coverage. Hair count data indicate that response to treatment occurred earlier with 5% compared with 2% topical minoxidil. Additionally, data from a patient questionnaire on quality of life, global benefit, hair growth, and hair styling demonstrated that 5% topical minoxidil helped improve patients' psychosocial perceptions of hair loss. An increased occurrence of pruritus and local irritation was observed with 5% topical minoxidil compared with 2% topical minoxidil.

CONCLUSION: In men with AGA, 5% topical minoxidil was clearly superior to 2% topical minoxidil and placebo in increasing hair regrowth, and the magnitude of its effect was marked (45% more hair regrowth than 2% topical minoxidil at week 48). Men who used 5% topical minoxidil also had an earlier response to treatment than those who used 2% topical minoxidil. Psychosocial perceptions of hair loss in men with AGA were also improved. Topical minoxidil (5% and 2%) was well tolerated by the men in this trial without evidence of systemic effects.


Familial pityriasis rubra pilaris.

Vanderhooft SL, Francis JS, Holbrook KA, Dale BA, Fleckman P.

Department of Medicine, University of Washington School of Medicine, Seattle, USA.

Arch Dermatol 1995 Apr;131(4):448-53 Abstract quote

BACKGROUND: Familial pityriasis rubra pilaris is a rare autosomal dominant skin disorder. Four individuals from one family are described who demonstrate clinical features compatible with a diagnosis of familial pityriasis rubra pilaris. Results of light and electron microscopic, immunocytochemical, and biochemical analysis of skin biopsy specimens from three of these four individuals are presented.

OBSERVATIONS: All affected individuals demonstrated erythematous scaly skin with follicular prominence and islands of sparing. Inheritance was consistent with an autosomal dominant trait. Light and electron microscopic findings were compatible with those reported in sporadic cases of pityriasis rubra pilaris. Immunocytochemistry showed suprabasal staining with monoclonal antibody AE1. Immunoblot analysis revealed abnormal keratins with K6/16 expression, the possibility of an abnormal K14 or K16, and a 45-kd acidic keratin not normally expressed in epidermis. Because similar biochemical analyses have not been reported previously in other cases of pityriasis rubra pilaris (familial or sporadic), comparisons cannot be made.

CONCLUSIONS: The observations suggest that the cutaneous abnormality in this family extends beyond clinical and morphological alterations to abnormalities in biochemical markers of epidermal differentiation.



The nails in adult type 1 pityriasis rubra pilaris. A comparison with Sezary syndrome and psoriasis.

Sonnex TS, Dawber RP, Zachary CB, Millard PR, Griffiths AD.

J Am Acad Dermatol 1986 Nov;15(5 Pt 1):956-60 Abstract quote

The fingernails of twenty-four patients with classical adult (type 1) pityriasis rubra pilaris were examined for changes in nail morphology and a comparison was made with the fingernail morphology of twenty-seven consecutive psoriatic patients with nail changes.

Distal yellow-brown discoloration, subungual hyperkeratosis, nail plate thickening, and splinter hemorrhages indicate a diagnosis of type 1 pityriasis rubra pilaris rather than psoriasis, while onycholysis (particularly marginal), salmon patches, small pits, and larger indentations of the nail plate indicate a diagnosis of psoriasis. Histology demonstrated that a nail biopsy would be a useful diagnostic procedure if nails were involved in isolation but provided no additional diagnostic features to those found from biopsy specimens of involved skin in the two conditions.

The similarity in nail morphology between the type 1 pityriasis rubra pilaris patients and five patients with chronic erythroderma resulting from Sezary syndrome indicated that these changes may represent a nonspecific reaction pattern that may result from prolonged erythema of the proximal nail bed and matrix. The rough nails (trachyonychia) described in advanced Sezary syndrome were not observed in any of our patients.



The clinical and histomorphological features of pityriasis rubra pilaris. A comparative analysis with psoriasis.

Magro CM, Crowson AN.

Department of Pathology, Beth Israel Hospital, Harvard Medical School, Pathology Services Inc., Cambridge, Massachusetts 02139, USA.


J Cutan Pathol 1997 Aug;24(7):416-24 Abstract quote

Pityriasis rubra pilaris (PRP) is an idiopathic erythematous scaling eruption which can be difficult to distinguish from psoriasis.

We explored the clinical features, including background medical illnesses and potential triggers in patients with PRP, and also its histomorphologic spectrum. Patients with PRP were selected by natural language search of dermatopathology databases containing 250,000 cases accessioned over a 3-year period. A detailed medical history was obtained on each patient via office chart review and patient interviews.

We compared the histologic findings in skin biopsies from patients with PRP to those of biopsies matched for site and age from control patients with psoriasis. Certain aspects of the clinical presentations encountered in the study group patients have not been previously emphasized, including eruptions compatible with a vesiculobullous disorder in 4 patients. Several patients had evidence of underlying iatrogenic or systemic immune dysregulatory states and certain triggers could be isolated such as emotional stress and prior exposure to microbial pathogens.

Histomorphologic features predictive of PRP included follicular plugging, an increased granular cell layer, and acantholysis. While seen in a minority of biopsies of PRP, morphologic discriminators supportive of a diagnosis of psoriasis included neutrophils in the parakeratotic scale crust, and dermal papillae capillary ectasia with vessels lying in direct apposition to the epidermis. Other morphologic features were encountered in biopsies of PRP which have received little emphasis in the dermatopathology literature, including epithelial atrophy, significant dermal inflammation, the presence of eosinophils and plasma cells within the inflammatory infiltrates, an abnormal granular cell layer, and epidermolytic hyperkeratosis, albeit none were statistically signficant predictors of PRP over psoriasis. Nevertheless, their identification emphasizes the varied histologic spectrum of PRP. The almost ubiquitous finding of acantholysis and the presence of an abnormal granular cell layer in many biopsies of PRP suggests that abnormal keratins or defects in the retinol signalling pathway may be of pathogenetic importance.


PRP with subcorneal acantholysis: Case report and review.

Sebastian A, Koff AB, Goldberg LJ.

Department of Pathology, Drexel College of Medicine, Philadelphia, PA.

J Cutan Pathol. 2009 Jul 7. Abstract quote

Although the clinical findings of pityriasis rubra pilaris (PRP) are striking, the microscopic diagnosis can be difficult because changes can be subtle and can overlap with other skin diseases. Suprabasal acantholysis can be seen in PRP, mimicking pemphigus vulgaris.

We report a patient with PRP whose initial biopsies demonstrated subcorneal acantholysis mimicking pemiphigus foliaceus.

Pityriasis rubra pilaris with acantholysis.

Howe K, Foresman P, Griffin T, Johnson W.

Department of Dermatology, University of Pennsylvania, Philadelphia, USA.

J Cutan Pathol 1996 Jun;23(3):270-4 Abstract quote

Two patients developed a papulosquamous eruption in a widespread distribution which progressed with islands of sparing of uninvolved skin characteristic clinically of adult-onset pityriasis rubra pilaris (PRP).

Biopsies from both patients showed multiple areas of nonfollicular and follicular suprabasilar and intra-epidermal acantholysis with minimal dyskeratosis. They also showed the usual histologic features of PRP with a thickened orthokeratosis and parakeratosis, a retained and sometimes thickened granular cell layer, and psoriasiform epidermal hyperplasia with a perivascular lymphohistiocytic infiltrate in the superficial dermis.

Two previous patients with PRP have been reported with nonfollicular, focal acantholytic dyskeratosis and both were interpreted as most likely representing an incidental finding. We believe the acantholysis in these two cases is related to the disease process, and in our second patient, was helpful in establishing the diagnosis.

Pityriasis rubra pilaris with acantholysis and lichenoid histology.

Hashimoto K, Fedoronko L.

Department of Dermatology & Syphilology, Wayne State University School of Medicine, Detroit, Michigan, USA.

Am J Dermatopathol 1999 Oct;21(5):491-3 Abstract quote

Acantholytic foci have been reported several times in pityriasis rubra pilaris (PRP). Lichenoid tissue reactions were also mentioned in the literature regarding PRP. We report a 58-year-old patient who, after having colon cancer, had PRP with biopsies showing acantholytic lesions and a heavy lichenoid lymphocytic infiltration.

Investigation by serial sectioning of the acantholytic lesion suggested an involvement of the intraepidermal eccrine duct and further investigation with carcinoembryonic antigen (CEA) staining demonstrated a CEA-positive eccrine duct in the acantholytic foci.

We suggest that acantholysis in PRP is induced by proteolytic enzymes, urea, and other substances in eccrine sweat in keratin-plugged acrosyringia. This patient had a combination of three relatively rare features of PRP-acantholysis, lichenoid reaction, and a cancer background.


Focal acantholytic dyskeratosis occurring in pityriasis rubra pilaris.

Kao GF, Sulica VI.

Department of Pathology, Georgetown University Medical School, Washington, D.C.

Am J Dermatopathol 1989 Apr;11(2):172-6 Abstract quote

Focal acantholytic dyskeratosis (FAD) is a distinctive histologic pattern characterized by suprabasilar clefts surrounding dermal papillae (villi), acantholytic and dyskeratotic cells at all levels of the epidermis, hyperkeratosis, and parakeratosis.

The features of FAD are typically seen in Darier's disease, warty dyskeratoma, and transient acantholytic dermatosis; they are also present in a variety of cutaneous neoplastic and nonneoplastic lesions. FAD, however, has not been previously described in lesions of inflammatory dermatoses.

We report a case of FAD occurring in lesions of pityriasis rubra pilaris (PRP). To the best of our knowledge, this is the first reported case of this kind. We also review the pertinent literature.



Pityriasis rubra pilaris: a clinico-pathological and therapeutic study with special reference to histochemistry, autoradiography, and electron microscopy.

Braun-Falco O, Ryckmanns F, Schmoeckel C, Landthaler M.

Arch Dermatol Res 1983;275(5):287-95 Abstract quote

Five patients with pityriasis rubra pilaris (PRP) were analyzed by means of light and electron microscopy as well as by histochemistry and autoradiography. The results were compared with findings in psoriasis vulgaris.

In PRP we found a moderate increase of the labeling index of epidermal cells, a highly increased labeling index of dermal infiltrating cells, and a mild spongiosis, and in the stratum granulosum, a decreased number of tonofilaments and an increased number of keratinosomes. The horny layer in PRP showed a pronounced histochemical and electron microscopical parakeratosis, even when histological parakeratosis was absent. In contrast with psoriasis vulgaris, there was no exocytosis of polymorphonuclear leucocytes into the epidermis, the papillomatosis index was normal, and there were no tortuous capillaries in the dermal papillae.

The stratum granulosum was always present and sometimes thickened, showing electron microscopical changes different from those referred to in psoriasis. These changes point to a relatively distinct pattern of epidermal changes in PRP.



Horny perifollicular mucinosis. An atypical pityriasis rubra pilaris-like eruption associated with HIV infection.

Perrin C, Durant JM, Lacour JP, Michiels JF, Dellamonica P, Ortonne JP.

Department of Pathology, Hopital Pasteur, Nice, France.

Am J Dermatopathol 1993 Aug;15(4):358-62 Abstract quote

We present a case of pityriasis rubra pilaris (PRP)-like eruption, in association with human immunodeficiency virus (HIV) infection, clinically characterized by follicular papules with some elongated spines and comedo-like lesions. The lesions were located on the back, flanks, and proximal extremities. Orthokeratotic follicular plugs and perifollicular mucinous degeneration were consistently observed on three biopsies. The most characteristic histological features of PRP were absent.

To our knowledge, this is the first reported case of this kind. Such a case could suggest an atypical PRP modified by HIV infection. It is also possible that it represents a new entity associated with advanced HIV infection (horny perifollicular mucinosis).


Psoriatic erythroderma: a histopathologic study of forty-five patients.

Tomasini C, Aloi F, Solaroli C, Pippione M.

Department of Dermatology, University of Turin, Italy.

Dermatology 1997;194(2):102-6 Abstract quote

BACKGROUND: There are conflicting opinions about the diagnostic value of skin biopsy in erythrodermic psoriasis.

OBJECTIVE: The purpose of the present study was to establish the specificity of the histopathologic changes of psoriatic erythroderma.

METHODS: We reviewed 52 skin biopsies from 45 erythrodermic patients having a final diagnosis of psoriasis on the basis of combined clinical and laboratory data, in addition to response to therapy and follow-up. In 5 patients, erythroderma was the presenting sign of psoriasis. A control group of nonpsoriatic erythrodermic patients was also included in the study.

RESULTS: Among the group of patients with a discharge diagnosis of psoriatic erythroderma, the histopathologic changes were specific for psoriasis in 40 cases (88%). The changes of early macular and squamous lesions of psoriasis were more often found in the biopsy specimens of our series than those of fully developed or late lesions of psoriasis. They included mainly slight epidermal hyperplasia, focal disappearance of the granular layer, mounds of parakeratosis and extravasated erythrocytes within edematous dermal papillae associated with perivascular and interstitial infiltration of lymphocytes and histiocytes.

CONCLUSION: When features of early lesions of psoriasis are found during the evaluation of a biopsy specimen from a patient with a clinically nonspecific erythroderma, the dermatopathologist should be aware that this patient could have psoriasis and a renewed anamnesis and a close follow-up should be made.



Pityriasis rubra pilaris in childhood: a long-term study of 29 cases.

Gelmetti C, Schiuma AA, Cerri D, Gianotti F.

Pediatr Dermatol 1986 Dec;3(6):446-51 Abstract quote

Pityriasis rubra pilaris (PRP) is a dermatosis of unknown origin with a limited frequency in childhood (0.2% of our hospitalized pediatric patients).

During the last 20 years we have observed 31 new cases; follow-up has been conducted in 29 children. The acute self-resolving form seems to be the most frequent in children, compared to adults. No cases of hereditary PRP have been observed, and no relationship between the severity of PRP and its prognosis has been reported.

Since juvenile PRP has a relatively rapid course and a spontaneous resolution (a few months), it seems unnecessary to use potentially harmful drugs. Synthetic retinoids may be employed in patients whose disease is both persistent and disabling.

Adult pityriasis rubra pilaris: a 10-year case series.

Clayton BD, Jorizzo JL, Hitchcock MG, Fleischer AB Jr, Williford PM, Feldman SR, White WL.

Department of Dermatology, Bowman Gray School of Medicine, Winston-Salem, NC 27157, USA.

J Am Acad Dermatol 1997 Jun;36(6 Pt 1):959-64 Abstract quote

BACKGROUND: Pityriasis rubra pilaris (PRP) often has a devastating impact on the lives of patients. Descriptions of its histopathologic features are not uniform. Finding a successful therapy can be challenging.

OBJECTIVE: Our purpose was to examine the histopathologic features and response of patients to our standard therapy of an oral retinoid and concomitant or later addition of low-dose weekly methotrexate.

METHODS: A retrospective chart review was done on 24 patients with PRP seen from March 1986 to March 1996. Biopsy specimens from 19 patients were reexamined. Telephone follow-up was conducted to determine maintenance of remission.

RESULTS: All patients had the adult acquired form of PRP. Biopsy specimens from nine patients were characterized by prototypical findings of PRP, while the others included both typical and other features. Twenty-two patients were treated with either isotretinoin, 40 mg twice daily, or etretinate, 25 to 75 mg/day. Six patients with more disabling involvement had low-dose weekly methotrexate ranging from 5 to 30 mg started concurrently. Five patients had weekly methotrexate added at a later time. Seventeen patients showed 25% to 75% response after 16 weeks of therapy. All patients whose skin cleared maintained their remission.

CONCLUSION: Initial oral retinoid plus concurrent or later low-dose weekly methotrexate resulted in 25% to 75% improvement of PRP in 17 of 24 patients after 16 weeks of therapy. Some of the atypical features seen in biopsy specimens emphasize the importance of clinical and histopathologic correlation in establishing the diagnosis.


Treatment of classic pityriasis rubra pilaris.

Dicken CH.

Department of Dermatology, Mayo Clinic, Rochester, MN 55905.

J Am Acad Dermatol 1994 Dec;31(6):997-9 Abstract quote

BACKGROUND: Treatment of classic pityriasis rubra pilaris, which almost always progresses to a generalized erythroderma with marked, often disabling keratoderma of the palms and soles, remains problematic.

OBJECTIVE: Our purpose was to evaluate the results of treatment in a recent period during which the retinoid group of drugs has been available.

METHODS: The clinical course of 75 patients with classic pityriasis rubra pilaris seen from 1982 to 1992 was reviewed.

RESULTS: Of 15 patients treated with isotretinoin, 10 had complete and 2 had partial clearing. Of six treated with etretinate, four had clearing. All eight patients treated with methotrexate had a favorable response. Other forms of treatment, including Goeckerman regimen, corticosteroids, vitamin A, and cyclosporine, were ineffective.

CONCLUSION: Early diagnosis and early treatment with retinoids appear to offer the best chance for clearing of pityriasis rubra pilaris. If retinoids fail or cannot be used, methotrexate should be considered.


Three cases of pityriasis rubra pilaris successfully treated with cyclosporin A.

Usuki K, Sekiyama M, Shimada T, Shimada S, Kanzaki T.

Department of Dermatology, Kagoshima University Faculty of Medicine, Japan.

Dermatology 2000;200(4):324-7 Abstract quote

BACKGROUND: Pityriasis rubra pilaris (PRP) is reported to respond poorly to cyclosporin A (CsA).

OBJECTIVE: We attempted to determine the efficacy of CsA in the treatment of classic adult-type PRP.

METHODS: Three patients with classic adult-type PRP were treated with 5 mg/kg/day CsA.

RESULTS: A sustained clinical response was achieved within 2-4 weeks of therapy. Relapses were noted when the CsA dose was decreased to 1.2 mg/kg/day.

CONCLUSION: CsA should be considered in the treatment of classical adult-type PRP


Isotretinoin treatment of pityriasis rubra pilaris.

Dicken CH.

J Am Acad Dermatol 1987 Feb;16(2 Pt 1):297-301 Abstract quote

Five patients with pityriasis rubra pilaris were treated with isotretinoin from September 1982 through 1985. Isotretinoin at an average dose of 1.16 mg/kg/day for 16 to 24 weeks caused complete or almost complete clearing in four of the five patients.

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