Acrodermatitis continua of hallopeau with bone resorption in
Acrodermatitis continua of Hallopeau (ACH) is an uncommon inflammatory disease manifesting as a sterile pustular eruption of the fingers and toes. The disease is of a chronic relapsing nature and is often refractory to treatment.

An otherwise healthy 8-year-old presented with pustular eruption of the fingers and toes associated with burning sensation, dryness, and scaling for 8 months. Nail changes ensued during the course of the illness, leading to nail detachment of all fingernails and numerous toenails; however, the left fourth and right second, third, and fourth toenails were intact. There was no history of joint pain, lower limb edema, or jaundice. The patient had no family history of psoriasis.

Physical examination revealed scaly erythematous plaques with overlying pus and crust formation involving all distal digits and multiple areas on the palms and soles. Nails showed severe onychodystrophy with confluent pustules covering the nail bed; however, the left fourth and right second, third, and fourth toenails were spared.

A skin punch biopsy was taken and revealed psoriasiform hyperplasia, parakeratosis containing numerous neutrophils (Munro-like microabscesses), and focal spongiosis with absent granular layer. The dermis showed increased vascularity within the dermal papillae. This was accompanied by the presence of chronic inflammatory cells infiltrating the upper dermis. These features were consistent with subacute psoriasiform dermatitis/pustular psoriasis.

On radiological examination, there was focal soft tissue swelling at the tips of fingers of both hands with irregular outline and fissure-like indentation. Underlying terminal tufts showed focal areas of bone resorption, particularly over the fourth and fifth left digits. X-ray of the feet did not show any remarkable joint or osseous abnormalities.

Based on the clinical and histological findings, a diagnosis of ACH was made. Other laboratory tests including complete blood count, liver function test, renal function tests, hepatitis B and C serology, anti-HIV test, QuantiFERON tuberculosis test, and chest X-ray were normal. The patient was started on etanercept 25 mg subcutaneously twice weekly.

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