Skin differentials - Pompholyx eczema vs palmoplantar pustulosis

The second in GP and hospital practitioner Dr Andy Jordan's series on differentiating two often similar-looking skin conditions Both pompholyx eczema and palmoplantar pustulosis can cause an acute vesico-pustular eruption on hands and feet. But it is important to differentiate them because there are different therapeutic options, both topical and systemic. Pompholyx eczema • Can develop at any age • Can occur in either sex • An attack is characterised by a sudden onset of crops of clear vesicles which are deep and look like sago grains – with no erythema • Sensation of heat and prickling precedes attacks • Vesicles may become confluent and present as large bullae, especially on feet • Severe itching can occur and attack resolves with desquamation in two to three weeks • In mild cases, sides of fingers may be affected but typically symmetrical involvement of palms or soles occurs • Recurrences usual • More common in warm weather. Treatment • Emollients • Topical steroids • Very occasionally, for severe attacks, a short course of oral steroids may be necessary. Palmoplantar pustulosis • Disease of adults, usually in middle age • Marked preponderance in women • May be a positive family history of psoriasis, though now thought to be a distinct entity from psoriasis • Presents with well-defined plaques on thenar/hypothenar eminence/palm, and on instep or medial or lateral border of foot – sometimes the heel. Digital lesions are uncommon • Usually strikingly symmetrical • Area is dusty, red and often scaly. Numerous pustules, 2-5mm in diameter are present within this area at various stages of evolution, the freshest being yellow, then green, with the oldest pustules usually dark brown • Usually causes a burning discomfort but can be slightly itchy • Chronic, with spontaneous remissions unusual – often only temporary • Associations are: thyroid disease, psoriasis at other sites, cigarette smoking at onset (although stopping smoking does not cause remission) and various arthropathies: sternoclavicular and manubrio-sternal arthritis. Treatment • Superpotent topical steroids – with or without occlusion – help in short term, but condition flares after stopping • Oral retinoids (Acitretin) • PUVA • Ciclosporin • Lymecycline. Dr Andy Jordan is a GP and hospital practitioner in dermatology in Chesham, Buckinghamshire palmoplantar pustulosis