Asteatotic Eczema

Asteatotic eczema (eczema craquelé) is an inflammatory dermatosis caused by dry skin with loss of lipids and impaired barrier function, producing fissured erythematous plaques on the lower legs in older adults.

• Risk factors: age over 60 years, winter and dry low humidity environments, overwashing and harsh soaps, central heating, diuretics, statins, retinoids, hypothyroidism, malnutrition, renal failure, malignancy.
• Rarely paraneoplastic when sudden onset, widespread and refractory.

Dry, scaly erythematous skin with fine polygonal fissures resembling cracked porcelain, on the shins, arms and trunk, with itch.

• Worse in winter, relieved by emollients.
• Differential diagnosis: venous eczema, nummular eczema, contact dermatitis, ichthyosis acquired, scabies, psoriasis, xerosis, drug eruption, cutaneous T cell lymphoma, bullous pemphigoid prodrome.
• Complications: secondary bacterial infection, cellulitis, scratching with excoriation, lichenification, sleep disturbance, skin ulceration, progression to generalised eczema.

Clinical.

• Thyroid function, renal function, full blood count, ferritin, glucose, liver function when persistent or generalised.
• Swab for infection if crusted or weeping.
• Skin scraping and biopsy if refractory, unilateral or atypical.
• Review of medicines.

Restore the barrier with emollients and control inflammation briefly.

• Supportive: apply emollient ointment (white soft paraffin and liquid paraffin) liberally at least twice daily and straight after bathing, use soap substitutes, short lukewarm baths or showers (under 10 minutes), pat dry, humidify rooms, avoid scratching, wear soft cotton, keep nails short.
• Pharmacological: moderately potent topical corticosteroid, betamethasone valerate 0.1 percent or mometasone furoate 0.1 percent ointment once daily for 1 to 2 weeks, then step down to hydrocortisone 1 percent for 1 week; wet wrap dressings for severe flares; non sedating antihistamine for itch (cetirizine 5 to 10 mg daily, with reduced dose in the elderly and renal impairment). Treat infection with flucloxacillin 500 mg four times daily for 7 days.
• Procedures: none.
• Special groups: elderly, avoid sedating antihistamines and potent steroids on thin skin; pregnancy, emollients and low to moderate potency steroids; children, emollients and mild steroids; renal failure, adjust antihistamine dose.
• Red flags: sudden severe widespread onset in an older adult (underlying malignancy), weeping crusted lesions (infection), unilateral disease, no response to therapy, systemic symptoms.
• Follow-up: review at 2 weeks and 6 weeks; maintain daily emollient; investigate persistent cases.