Resident Rounds. Part III: Necrolytic Acral Erythema

November 2012 | Volume 11 | Issue 11 | Features | 1370 | Copyright © November 2012


Abstract

INTRODUCTION

A 59-year-old African American male presented with a widespread pruritic skin eruption that had been present for 1 year. His past medical history was significant for chronic hepatitis C (HCV) infection with cirrhosis, and he was undergoing evaluation for liver transplantation. Physical examination revealed hyperpigmented erythematous to violaceous scaly plaques on the bilateral legs in an extensor distribution, dorsal feet, dorsal arms and hands, as well as on the abdomen (Figures 1 and 2). Histopathology of a skin biopsy showed mild epidermal acanthosis with parakeratosis, rare midepidermal necrotic keratinocytes, and a perivascular lymphocytic infiltrate (Figure 3). Based on these findings and the clinical scenario, the diagnosis of necrolytic acral erythema (NAE) was made, and the patient was started empirically on 220 mg of zinc sulfate per day.

DISCUSSION

Necrolytic acral erythema was first described in 1996 in Egypt as a subtype of necrolytic erythema associated with HCV; the incidence approaches 1.7% of patients with HCV.1-3 Clinically, NAE presents with well-demarcated scaling erythematous papules and plaques with secondary lichenification and later hyperpigmentation.3 Histologically, NAE is characterized by acanthosis, hyperkeratosis, necrosis of keratinocytes, and perivascular infiltrate of lymphocytes. Pathological findings may vary with the stage of disease.
The pathophysiology of NAE with respect to HCV is unclear. Evidence suggests an association with HLA-DRB1, complement factors, and both antismooth muscle and antinuclear antibodies.4 There have also been data to support a correlation between viral load and specific viral genotypes and NAE.5 It is unclear if the presence of NAE relates to HCV prognosis.
Low levels of zinc have been reported in several cases of NAE, and zinc sulfate therapy has been reported to clear lesions in some patients, regardless of normal or abnormal zinc levels.6,7 Other cases have reported clearance of the lesions with interferon and ribavirin-induced virologic suppression. 8,9 The variable response to treatment supports a multifactorial pathophysiology.
table 1
Necrolytic acral erythema is uniquely associated with HCV. In our patient, treatment was provided empirically with zinc sulfate. The patient has yet to return to this clinic for evaluation of clearance of NAE lesions.