Pustulosis of the Soles

A 68-year-old woman was referred from an acute care clinic for evaluation of a persistent cellulitis. Ten days before, erythematous, pruritic plaques developed on her ankles; these slowly enlarged, and pustules formed. The patient denied fever or chills. Her past medical history was unremarkable, and conjugated estrogen, medroxyprogesterone acetate tablets, and multivitamins were the only medications and nutritional supplements she was taking.

Physical examination revealed sharply demarcated, scaly, erythematous plaques with deep-seated pustules and “mahogony spots.” A potassium hydroxide evaluation of the scale showed no evidence of hyphae. The woman's scalp, hands, fingernails, elbows, sacrum, gluteal crease, and knees were free of cutaneous changes.

Dr Daniel J. Schissel, Maj, USA, MC, of the Brooke Army Medical Center, Fort Sam Houston, Tex, comments that pustulosis of the palms and soles is a distinctive psoriatic clinical entity with features that need to be considered separately from generalized pustular psoriasis. Although pustulosis of the palms and soles may coexist with psoriasis vulgaris, it usually occurs in the absence of plaque-type psoriasis.

The morphologic presentation of pustulosis of the palms and soles is readily identifiable. Erythematous papules develop on the palms and/or soles and coalesce into plaques that form pustules. Initially, these sterile pustules appear cloudy, then progress to a mahogany brown color, and finally develop a hard, keratinaceous surface. Lesions at these various stages are usually present. Common sites of involvement are the center of the palm and the instep; however, pustules may extend to the volar surfaces.

Dr Schissel tells us that the important first step in therapy is to reassure the patient by stressing that psoriasis is benign and noncontagious and that a wide array of treatment options exists. Potent topical corticosteroids are the mainstay of initial therapy; topical tar preparations, retinoids, and vitamin D analogs also are appropriate. Intralesion corticosteroid injection, light therapy, oral retinoids, cytotoxic drugs, and cyclosporin may be used but are best managed by a dermatologist. Dr Schissel cautions that oral corticosteroids should never be used to treat this condition, because they may exacerbate the disease process.