Subcorneal Pustular Dermatosis in Association with Chronic Lymphocytic Leukaemia

Sir,Subcorneal pustular dermatosis (SPD) is a chronic,relapsing, pustular eruption, the aetiology and patho-genesis of which are unknown. It has previously beenreported in association with rheumatoid arthritis (1),Crohn’s disease (2), pyoderma gangrenosum, Sweet’ssyndrome and other neutrophilic dermatoses, benignmonoclonal gammopathies (3) and IgA myeloma (4).Here we describe a patient with SPD in association withchronic lymphocytic leukaemia (CLL) and discuss thepossibility of a pathogenetic link. No cases havepreviously been reported of SPD and CLL.CASE REPORTA 78-year-old woman was referred to the DermatologyDepartment in August 1996 with a pruritic rash affect-ing her scalp, axillae, inguinal and infra-mammaryflexures. She had no personal or family history ofpsoriasis. Examination showed erythema, papules andpustules. A biopsy was inconclusive, showing in someareas hyperkeratotic, parakeratotic and mildly acan-thotic epidermis with spongiosis and focal neutrophilexocytosis, while in other areas there were well-formedsubcorneal pustules. Special stains were negative forbacteria and fungi. The patient was treated with topicalsteroids, emollients, tar preparations and calcipotriol,each with little benefit. She then received oral acitretin(10–25 mg daily for a total of 29 months), bath PUVA(twice weekly for 3 months) and oral methotrexate (upto 20 mg once weekly for 6 months); each produced atbest a short-lived partial improvement in the rash.In September 1999 the patient had a widespreaderythematous pustular eruption affecting the trunk andlimbs with a flexural distribution. She was systemicallywell and denied any joint or gastrointestinal symptoms.On this occasion, a mild lymphocytosis (white cellcount 11.8610