Necrolytic acral erythema
The pathophysiology of NAE is poorly understood.
The mean age at diagnosis is 40 years old (range 11-76 years old), 60% of patients are female, and a majority of afflicted individuals are African (including Egyptian) or African-American. Patients presenting with NAE often have advanced hepatic fibrosis or chronic hepatitis. Pediatric cases are rare, attributed to the lower rates of HCV among children compared with adults, although the presentation of NAE in children is similar to that of adults.
NAE initially presents with pronounced erythematous papules and occasional vesicles and flaccid bullae; the papules become confluent over time and progress to well-demarcated, dusky, erythematous to violaceous plaques with thick scale, erosion, crusting, and a dark erythematous border. The lesions are associated with pruritus, burning, and less commonly pain.
NAE most commonly affects the dorsal acral surfaces involving toes / feet, but variants also include involvement of the Achilles tendon, malleoli, legs, knees, dorsum of hands, forearms, elbows, buttocks, and genitals. Oral mucosa, palmoplantar surfaces, and nails are often spared.
L53.9 – Erythematous condition, unspecified
238993006 – Acral erythema
Differential Diagnosis & Pitfalls
- Necrolytic migratory erythema – Look for elevated glucagon levels, not necessarily associated with HCV or consistent localization to dorsal aspects of feet.
- Acrodermatitis enteropathica – Has periorificial involvement, depressed zinc serum levels.
- Pellagra – Associated with facial lesions, Casal necklace, diarrhea, dementia, depressed levels of niacin, and photodistributed lesions.
- Essential fatty acid deficiency
- Biotin deficiency
- Hypertrophic lichen planus
- Psoriasis – Distributed over extensor surfaces, scalp.
- Eczema – Poorly demarcated borders.
- Hyperkeratotic allergic contact dermatitis – Confined to area of contact with allergen.