Autoinflammatory Diseases Presenting in the Skin

Abstract Autoinflammatory diseases comprise a heterogeneous group of inherited monogenic and acquired polygenic multisystem disorders that may present in the skin and are therefore of importance to dermatologists. The inherited monogenic disorders typically present in childhood. Those that present with urticarial rashes are particularly important to differentiate from chronic urticaria since the pathogenesis, prognosis and treatment are completely different. Cryopyrin‐associated periodic syndrome should be suspected in children with a family history of chronic urticaria that does not respond to H 1 antihistamines and who have systemic symptoms of malaise and fever with persistently raised inflammatory indices. Autoinflammatory syndromes also may present with: unexplained fever, erysipelas‐like rash (familial Mediterranean fever), oedema (tumour necrosis factor receptor‐associated periodic syndrome), granulomatous dermatitis (Blau syndrome), an aseptic pustular dermatosis (deficiency of interleukin 1 receptor antagonist) or pyoderma gangrenosum (pyogenic sterile arthritis, acne and pyoderma gangrenosum), chilblain or acral erythematous atrophic or necrotic lesions in a toddler with neurological (Aicardi‐Goutières syndrome) or interstitial pneumonia (STING‐associated vasculopathy of infancy), lipoatrophy (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature), livedo, nodules (vasculitis) and stroke (deficiency of adenosine deaminase 2), aphtous stomatis with early‐onset bowel disease (haploinsufficiency of A20 or of RELA). Acquired autoinflammatory syndromes which present in adult life include Schnitzler syndrome and adult Still disease; the differential diagnosis includes urticarial vasculitis.