Those annoying acne bumps on the back of my neck won't go away

April 1, 2007

A 16 year old African American teenager complains of itchy bumps on the back of his neck for a 2-year period. What's the diagnosis?

A 16-year-old African American male complained of painful, itchy bumps on the back of his neck for two years. The eruption developed shortly after he joined the football team, and the coach insisted on short hair cuts with shaving of the hair on the nape of the neck. There was a family history of keloids.

Diagnosis: Acne keloidalis nuchae

Pathogenesis

Although the cause of AKN is unknown, the growth of short cropped or shaved hair which curls back into the skin producing an irritant reaction may be the initial trigger.3 Individuals with a family history of keloids may be prone to develop the classic clinical findings. Other factors such as irritation from shirt collars and low-grade chronic folliculitis may facilitate the process.

Clinical features

Patients complain of pruritus and pain, and pustules are usually short-lived because of the subsequent scratching. Band-like plaques at the base of the scalp extending on to the back of the neck may be associated with large areas of alopecia. Occasionally pain may be severe when abscesses and draining sinuses develop. AKN may be associated with a similar process in a beard distribution known as perifolliculitis barbe.

Diagnosis

Although the diagnosis can usually be made clinically, a skin biopsy may be useful to confirm the clinical suspicion.4 When abscesses are present, cultures may be necessary to direct appropriate antibiotic therapy.

AKN rarely requires differentiation from other skin conditions. However, this entity may be confused with keloids resulting from other trauma to the area. Sarcoidosis may develop at the nape of the neck, but can be distinguished by the presence of deeper subcutaneous nodules, which may be follicular or interfollicular, without preceding pustules.1,3 AKN is not associated with comedones, which are typical of acne.

Treatment

AKN can be chronic and progressive with enlarging areas of fibrosis. Treatment may be complex and chronic as well.

Preventive measures include avoidance of shaving the hair on the back of the scalp and nape of the neck. Mechanical irritation from tight-fitting shirt collars, hats, and other clothing should be discouraged. The best form of treatment is prevention. Initiation of these measures once lesions have appeared may also help to prevent disease progression.

Active lesions may improve with topical steroids, retinoids, and/or antibiotics. Intralesional steroids maybe used to shut down progressive fibrosis, but lesions may recur when treatment is discontinued. Painful abscesses should be cultured and appropriate oral antibiotic therapy initiated. Larger papules and plaques may be treated with liquid nitrogen, surgical excision, or carbon dioxide laser excision. However, these modalities may also be associated with recurrence of lesions post-operatively.

MS. HAQUE, MS-IV, is studying at Drexel University College of Medicine, Philadelphia.

DR. COHEN, who serves as section editor for Dermatology: What's your Dx?, is director, Pediatric Dermatology and Cutaneous Laser Center, and associate professor of pediatrics and dermatology, Johns Hopkins University School of Medicine, Baltimore. He is a contributing editor for Contemporary Pediatrics.

The author and the section editor have nothing to disclose in regard to affiliations with, or financial interests in, any organization that may have an interest in any part of this article.

REFERENCES:

1. Kelly AP: Pseudofolliculitis barbae and acne keloidalis nuchae. Dermatol Clin 2003;21:645

2. Knable AL, Hanke CW, Gonin R: Prevalence of acne keloidalis nuchae in football players. J Am Acad Dermatol 1997;37:570

3. Luz Ramos M, Munoz-Perez MA, Pons A, et al: Acne keloidalis and tufted hair folliculitis. Dermatology 1997;194:71

4. Kolve J, Crutchfield C: Acne keloidalis nuchae. Dermatol Nurs 2003;6:551

Please see Dr. Cohen's Web site, www.dermatlas.org, for additional images