Pityriasis rubra pilaris in a HIV-positive patient (Type 6 PRP)

A 45-year-old previously healthy man presented with minimally itchy spiny papular lesions of 3 years' duration and discharging nodular cystic lesions for the past 2 years. Initially, lesions appeared on his ears, followed by the gradual appearance of similar lesions over his face, back, and extremities. The lesions were not associated with photosensitivity. Over the years, the patient continued to have similar lesions without any significant response to various topical medications and oral antibiotics. There was no history of fever or any other systemic complaints and the patient denied any other significant medical problems in the past. Cutaneous examination revealed multiple, grouped, spiny papular lesions coalescing to form plaques at places over the ears, extremities, and trunk (Figure 1). Elongated, horny, follicular spires were noted on the top of the papular lesions. Multiple discharging nodular lesions with crusting were seen predominantly over the chest, abdomen, and back (Figure 2), and closed comedonal lesions were noted on the face and trunk. Multiple orange-brown scaly plaques were seen over the extensor aspect of the patient's thighs (Figure 1, inset). A few nails showed wedge-shaped thickening without subungual hyperkeratosis or other nail changes. Palms, soles, and oral mucosa were normal. Considering the atypical cutaneous findings, the clinical possibility of pityriasis rubra pilaris (human immunodeficiency virus [HIV]-associated type 6 PRP) was considered. Hematoxylin and eosin stain of skin biopsy specimens taken from the spiny papular and plaque lesions revealed marked hyperkeratosis with alternating orthokeratosis and parakeratosis with follicular keratotic plugging (Figure 3; Figure 3, inset). Irregular broad acanthosis was also detected in the epidermis. Dermis showed moderate perivascular lymphomononuclear inflammatory infiltrate. Thus, the skin biopsy was consistent with PRP. HIV serology by enzyme-linked immunosorbent assay (ELISA) with 3 different kits was found to be positive for HIV-1. The patient denied any risk factors associated with acquiring HIV infection, and laboratory values for complete blood cell count, routine serum biochemical profile, and lipid profile were normal. The patient was prescribed oral isotretinoin and asked to come for follow-up for CD4 T-cell count, but did not return.