Diagnosis: PITYRIASIS RUBRA PILARIS(1997 Uniformed Services Dermatology Seminar, Case#3) presented by: Rinna C. Johnson, Maj, MC, USA

History: Patient presented with a 3-4 year history of a chest and back rash that had been treated with topical Selsun and antifungals without improvement. Due to a new crop of lesions on his upper arms and thighs, he sought a new consultation with dermatology. Initial KOH was positive and the patient was treated with a 2 week course of oral ketoconazole but with no improvement. The first fungal culture grew out Scopulariopsis ssp and a shave biopsy showed a psoriasiform dermatitis with negative PAS stain. Because of persistence of lesions, the patient was recultured 2 weeks after the last ketoconazole and this second culture was negative. While awaiting culture results, the patient was treated with an empiric course of oral itraconazole. The patient developed new lesions while on itraconazole, so a 4 mm punch biopsy was performed which showed findings suggestive of small plaque parapsoriasis. The patient was started on UVB therapy and topical kenalog spray. The UVB therapy was discontinued due to noncompliance because of college classes and work. He showed no improvement with this therapy. When patches began to enlarge, an incisional biopsy was performed which showed changes consistent with pityriasis rubra pilaris.

Exam: PHYSICAL EXAM: The initial exam revealed small almost guttate lesions of erythema and scale with follicular prominence scattered over his back, shoulders, and anterior chest. These lesions progressed to involve his upper arms, abdomen, thighs, and lower legs. Later examination revealed annular patches measuring from 1-5 cm scattered among the smaller lesions, with the periphery of these patches and intervening skin demonstrating prominent follicular hyperkeratosis. LABORATORY: First fungal culture: Scopulariopsis (considered to be a contaminant). Second fungal culture: negative. Third fungal culture (done on tissue): negative. RPR and HIV negative, CBC and Chemistries normal, UA normal. HISTOPATHOLOGY: Sections demonstrated psoriasiform epidermal hyperplasia with hyperkeratosis, parakeratosis, and follicular keratotic plugging. There was minimal dermal inflammation.