Erythemas Summarized Erythema ab igne • A dermatosis that results from repeated exposure to heat (fires, heating pads, heating blankets, sometimes laptops). Erythema annulare centrifugum • A chronic skin condition thought to be a form of delayed-type hypersensitivity. • Can be induced by a variety of potential inciting causes: infections (cutaneous or systemic), malignancies, autoimmune conditions, medications, foods, stress, etc. Erythema arthriticum epidemicum • Condition known as rat bite fever or Haverhill fever caused by the organism Streptobacillus moniliformis. Rash is usually morbilliform and on the extremities Erythema chronicum migrans • Rash of Lyme in early localized disease. • Many have moved away from including the word "chronicum" because nothing chronic about it! Erythema dyschromicum perstans • A form of acquired dermal macular hyperpigmentation. It is classified as a variant of lichen planus. Well-circumscribed roundish-oval patches on the face, neck, or trunk most commonly. • No well-described associations. Erythema elevatum diutinum • A rare form of necrotizing vasculitis. Usually composed of papules + nodules on the back of hands, extensor surfaces, and buttocks. • Can be associated with a variety of infections + hematological and rheumatological conditions Erythema gyratum repens • A skin condition presenting with erythematous concentric rings that appear to have a "wood-grain" appearance. • Most commonly associated with cancers, including lung, esophageal, breast, and stomach. Has more rarely been associated with mycobacterial infection and autoimmune conditions. Erythema induratum • A chronic skin condition, usually on the extremities, of painful, indurated nodules associated with tuberculosis. • This one is also called "Bazin's disease." Erythema infectiosum • Fever + facial rash that occurs in children with acute Parvovirus B19 infection (so-called fifth disease). Erythema marginatum • Evanescent rash observed in acute rheumatic fever after group A Strep pharyngitis. Erythema multiforme • Acute systemic rash resulting in classic targetoid lesions. • Causes are multiple and include: infections (HSV + Mycoplasma classic), autoimmune conditions, malignancies, idiopathic, and medications Erythema nodosum • Tender, reddish-purple nodules classically on the lower extremities. • Associated with variety of causes: sarcoidosis (and other autoimmune conditions), infections (streptococcal, endemic mycoses, TB, and others), malignancies, and drugs Erythema toxicum neonatorum • Pustular eruption that occurs within the first few days of life in newborns. Classic association is that smear of the pustular material shows numerous eosinophils. • Cause is unknown. Prathit Kulkarni, MD @PrathitKulkarni #Erythemas #comparison #table #differential #diagnosis #dermatology #compared
