The most common side effect of topical corticosteroid use is skin atrophy. All topical steroids can induce atrophy, but higher potency steroids, occlusion, thinner skin, and older patient age increase the risk. The face, the backs of the hands, and intertriginous areas are particularly susceptible. Resolution often occurs after discontinuing use of these agents, but it may take months. Concurrent use of topical tretinoin (Retin-A) % may reduce the incidence of atrophy from chronic steroid applications. 30 Other side effects from topical steroids include permanent dermal atrophy, telangiectasia, and striae.
Diagnosis of chronic paronychia is based on physical examination of the nail folds and a history of continuous immersion of hands in water 10 ; contact with soap, detergents, or other chemicals; or systemic drug use (retinoids, antiretroviral agents, anti-EGFR antibodies). Clinical manifestations are similar to those of acute paronychia: erythema, tenderness, and swelling, with retraction of the proximal nail fold and absence of the adjacent cuticle. Pus may form below the nail fold. 8 One or several fingernails are usually affected, typically the thumb and second or third fingers of the dominant hand. 13 The nail plate becomes thickened and discolored, with pronounced transverse ridges such as Beau's lines (resulting from inflammation of the nail matrix), and nail loss 8 , 10 , 13 ( Figure 4 ) . Chronic paronychia generally has been present for at least six weeks at the time of diagnosis. 10 , 12 The condition usually has a prolonged course with recurrent, self-limited episodes of acute exacerbation. 13