Question:

A 50-year old lady presented with two-year history of recurrent yellow pustules on both palms and soles. The yellow pustules resolved to form red brown macules with scaling. Skin scraping was negative for bacteria and fungus. There were psoriatic plaques on elbows, knees and psoriatic nail changes. There were no fever, malaise, urinary or gastro-intestinal symptoms, joint pain, and eye discomfort.

Answer: B. Pustular psoriasis of palms and soles

Palmoplantar pustular psoriasis is a localised form of pustular psoriasis characterised by chronic recurrent crops of sterile yellow pustules affecting the palms and soles. The yellow pustules become brown, on a background of well-defined erythema and scaling. It may be accompanied by psoriatic nail and skin lesions elsewhere. Skin biopsy shows psoriasiform hyperplasia with acanthosis and elongation of rete ridges, neutrophil infiltration and subcorneal pustule within the epidermis. No bacteria or fungus is seen. The dermis shows moderate perivascular mononuclear cell infiltration. Generalised pustular psoriasis is a serious and unstable form of psoriasis with significant mortality. Erythematous plaques studded with tender sterile pustules rapidly appear over any site and become confluent. Fever and malaise are common. It may be precipitated by abrupt steroid withdrawal. Keratoderma blenorrhagica resembles pustular psoriasis of the sole. It occurs in Reiter's disease, with accompanying urethritis or gastroenteritis, conjunctivitis and arthritis. Oral ulceration and in the male circinate balanitis may also be present. Pompholyx eczema is a recurrent itchy vesicular eruption affecting sides of fingers, palms and soles. The clear vesicles are deep seated and sago-like in appearance. Confluence produces large bullae. Secondary infection may occur.