Annoying neck nodules in an adolescent boy

The Case

A healthy adolescent boy asks you to cure an itchy and painful rash on the nape of his neck that began over a year ago when he had switched barbers. What’s your diagnosis?

Diagnosis:

Acne keloidalis nuchae resulting from pseudofolliculitis

Epidemiology

Populations with tightly curled hair are predisposed to developing pseudofolliculitis barbae (PFB).^1-3 The nature of African American hair enables easy skin penetration because of its coiled pattern of growth and elliptical cross-section. Some statistics confirm that between 45% and 83% of young adult African American males suffer from some form of PFB.^1,3,4 It is particularly a problem among military personnel whose profession requires a clean-shaven appearance.³ Although less frequent, females also may develop PFB, especially in the groin or in cases of hirsutism.^1,4

Pathophysiology

Pseudofolliculitis barbae is a chronic inflammation of the hair follicle that develops in response to shaving. Multiple factors play into the etiology, including the shape of the hair follicle, the type of hair, the direction of growth, and the modality of hair removal.^1,3,4 When cut, sharpened hair shafts coil as they grow out, leading to either extrafollicular repenetration or transfollicular transection of the skin. This incites a foreign body inflammatory response that is clinically characterized by painful or pruritic papules, pustules, and nodules. Recurrences induced by repeated shaving may lead to hyperpigmentation with hypertrophic or even keloid-like scarring in individuals prone to keloid formation. It is most common in the anterior neck of males. However, it can also occur in the groin, axilla, or the nape of the neck.^1,3

Diagnosis and Treatment

Pseudofolliculitis barbae is a clinical diagnosis that is frequently confused with acne vulgaris. In patients with a predisposition to keloid formation, pseudofolliculitis and acne vulgaris may trigger hypertrophic scars and keloids. Early diagnosis and treatment are critical to prevent the development of permanent scarring and associated pruritus, pain, and disfigurement.Treatment for acne vulgaris, bacterial folliculitis, and pseudofolliculitis include topical and oral antibiotics, topical benzoyl peroxide, and topical retinoids.

Shaving in the direction of hair growth using single-bladed razors and clippers should be recommended.^3,4 This approach decreases the risk of an excessively close shave and resultant ingrown hair. Complete cessation of shaving usually results in resolution of inflammatory PFB lesions within 1 month.^1,3

When employers require a clean-shaven appearance, a trial of chemical depilatory agents with barium sulfide or calcium thioglycolate may be useful as long as they do not induce contact dermatitis that also may trigger PFB.^3,4 Furthermore, if shaving cannot be avoided, it should be preceded by washing with an antiseptic agent and hydration with a hot, moist towel, followed by the application of lubricating agents.² Topical corticosteroids are also helpful in reducing active inflammation. Infrared laser therapy is the most definitive option because it destroys hair follicles, resulting in permanent hair reduction.^2-5 Surgical excision and intralesional corticosteroids are reserved for the treatment of persistent, symptomatic hypertrophic scars and keloids.²

Our patient

This adolescent developed PFB when his new barber began shaving the back of his neck with a straight razor. He asked the new barber to stop shaving the back of his scalp, and he began oral minocycline, 100 mg twice daily, with rapid clearing of inflammatory lesions. The persistent itchy and painful keloidal nodules flattened with high-potency topical steroids and intralesional steroids treated the larger and more resistant nodules.

REFERENCES

1. Perry PK, Cook-Bolden FE, Rahman Z, Jones E, Taylor SC. Defining pseudofolliculitis barbae in 2001: a review of the literature and current trends. J Am Acad Dermatol. 2002;46(2 Suppl Understanding):S113-119.

2. Quarles FN, Brody H, Johnson BA, Badreshia S, et al. Pseudofolliculitis barbae. Dermatol Ther. 2007;20(3):133-136.

3. Garcia-Zuazaga J. Pseudofolliculitis barbae: review and update on new treatment modalities. Mil Med. 2003;168(7):561-564.

4. Bridgeman-Shah S. The medical and surgical therapy of pseudofolliculitis barbae. Dermatol Ther. 2004;17(2):158-163.

5. Schulze R, Meehan KJ, Lopez A, et al. Low-fluence 1,064-nm laser hair reduction for pseudofolliculitis barbae in skin types IV, V, and VI. Dermatol Surg. 2009;35(1):98-107.

MR MITKOV is a fourth-year medical student at Creighton University School of Medicine, Phoenix Regional Campus, Arizona. DR COHEN, the 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, Maryland. The author and section editor have nothing to disclose regarding affiliations with or financial interests in any organizations that may have an interest in any part of this article. Vignettes are based on real cases that have been modified to allow the author and editor to focus on key teaching points. Images also may be edited or substituted for teaching purposes.