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27-Year-Old Male with Bumps on Scalp and Neck

Can you diagnose this case?

Eric C. Schmidgal, MD

Signs and Symptoms

A 27-year-old Hispanic man and active-duty military member presented to his ship’s physician with bumps on the back of his neck. He had had the bumps for several years, and he reported that they sometimes were itchy and painful. He denied weeping or drainage from the lesions. He also denied fevers, myalgias, arthralgias, or other systemic complaints. He was not taking any medications, nor did he have family members with similar lesions.

Further history taking revealed that his lesions became most inflamed after haircuts during which electric clippers were used. As a military member, he is required to keep his hair trimmed close to the skin to comply with regulations. He had been told in the past that he had some type of scalp infection, but he had never received treatment.

What is the cause of this man’s scalp lesions?

Choose one to reveal diagnosis and discussion

Acne keloidalis nuchae
Pseudofolliculitis barbae
Tinea capitis
Seborrheic dermatitis

Answer: Acne Keloidalis Nuchae

See the full case at Consultant360

Based on the patient’s history and physical examination findings, a diagnosis of acne keloidalis nuchae (AKN) was made.


AKN was first described in the literature by Kaposi in 1869, and Bazin coined the term acne keloidalis in 1872; both described a follicular-based dermatitis occurring on the posterior scalp.1 The name is a bit of a misnomer given that the lesions are neither acne nor true keloids. The lesions most commonly occur on the occipital scalp and posterior neck and are a folliculitis.

The exact cause of AKN is unknown. It is thought to result from the irritation of coarse hairs on the posterior neck and occipital scalp, leading to a chronic inflammatory state in the skin. Initially, the condition presents as a folliculitis characterized by papules and pustules. Over time, the inflammatory state of the skin results in the formation of keloid-like plaques. Close shaving, frequent haircuts, and rubbing of clothing or equipment can exacerbate AKN. In advanced cases of AKN, the lesions can become infected, and abscesses and sinus tracts can form.

Outcome of the Case

The diagnosis of AKN was explained to the patient. He was instructed on the importance of hygiene in the region. He was also told to avoid tight-fitting collars and not to pick at or attempt to drain the lesions on his own. Because of his status as an active-duty military member, he still requires keeping his hair cut short, but he was advised to have the barber use a guard on the clippers to minimize irritation.

Listen to a short podcast with the author here.

Eric C. Schmidgal, MD, is a physician in San Diego, California.


1. Gloster HM Jr. The surgical management of extensive cases of acne keloidalis nuchae. Arch Dermatol. 2000;136(11):1376-1379.

2. Sperling LC, Homoky C, Pratt L, Sau P. Acne keloidalis is a form of primary scarring alopecia. Arch Dermatol. 2000;136(4):479-484.