Acne keloidalis nuchae: An international multicentric review of 79 patients

Abstract

Dear Editor, Acne keloidalis nuchae (AKN) is a rare chronic and scarring alopecia characterized by fibrotic papules, nodules, plaques and/or tumorous masses of the neck and scalp (Figure 1). 1 It mainly affects men of dark phototypes in different ethnic groups and has been considered the most common form of scarring alopecia in African males. Few case series have been reported. The objective of our study was to describe the epidemiological, clinical presentation and therapies in a large series of patients with AKN.We performed an observational, retrospective and multicentric international review of 79 patients with a confirmed diagnosis of AKN. We collected data regarding demographics, disease duration, family history and intensity of the disease, comorbidities, different disorders affecting the follicle unit, possible triggers, treatment and response to treatments.Overall, 79 patients (75 men and 4 women) with a median age at diagnosis of 35 years (range 15-72 years) were included. The main results are shown in Table 1. We performed a bivariant statistical analysis using chi-squared test to assess the association between these characteristics. We found a significant statistically association (p < 0.01) between AKN classification by lesion type and the grade of improvement after treatment. Patients with a less than 3 cm distribution of the lesions or with discrete papules and nodules had a greater probability of important or complete improvement after treatment in comparison to the more than 6 cm distribution of the lesions group and the patients with merged papules and nodules. Obesity was a risk factor to have tumorous masses in comparison to patients with normal weight. Straight hair was associated with less than 3 cm distribution of the lesions and wavy hair was associated with 3-6.5 cm distribution.Hidradenitis suppurativa and AKN were present in 11.7% which was higher than 1% reported by Kridin et al. 2 An overall prevalence of 37.2% of follicular disorders (acne vulgaris 18.6%, pseudofolliculitis barbae 14%, chronic scalp folliculitis 11.6%, folliculitis decalvans 7%, dissecting cellulitis 7%) were found by East-Innis et al. 3 One or more criteria of metabolic syndrome were present in 34.9% of AKN patients (diabetes mellitus 11.6%, hypertension 14%, obesity/ overweight 21%, hypercholesterolaemia 2.3%). 3 Saka et al. 4