What is pseudofolliculitis barbae?
Pseudofolliculitis barbae (PFB) is a common inflammatory reaction of the hair follicle, most often on the face as a result of shaving. Also known as “razor bumps” or “shaving bumps”, it can also occur on any site where hair is shaved or plucked, including the axilla, pubic area, and legs.
Folliculitis barbae presents similarly, but is due to infection. Folliculitis barbae and pseudofolliculitis barbae can coexist.
Pseudofolliculitis barbae
Who gets pseudofolliculitis barbae?
Although PFB can occur in men of all races, it predominantly affects men of African ancestry (approximately 45–80%). This is likely due to a greater prevalence of tightly curled, coarse hair in the African population. A study demonstrated that the presence of a single nucleotide substitution in the hair follicle companion layer-specific keratin (K6hf) is an additional risk factor. It can also affect women of all races, especially occurring in the groin.
It is associated with improper shaving technique and is more common with blade razor users compared to electric shavers.
What causes pseudofolliculitis barbae?
Razor bumps are thought to be caused by intrafollicular or transfollicular penetration of tight curly hair, often of coarse nature. They may also occur in skin folds or scar tissue, allowing straight hair to re-enter.
This often occurs due to close shaving, as cut hair results in a sharp pointed end and may re-enter by either:
- Piercing the skin surface (transfollicular)
- Retract beneath the skin surface and pierce the follicular epithelium (intrafollicular).
This subsequently leads to a foreign body inflammatory reaction. The injured follicles are highly susceptible to infection, causing folliculitis barbae.
What are the clinical features of pseudofolliculitis barbae?
- An acne-like eruption presenting as ingrown hairs associated with flesh-coloured or red follicular papules.
- Most often on the face and neck of men after shaving.
- Under the jawline is typical, a site where the hair follicles grow in various directions.
- PFB may also occur in any site where hair is shaved or plucked, including the axilla, pubic area, and legs.
- May be itchy or tender.
- Lesions may bleed when shaved.
- May coexist with, and be aggravated by eczema/dermatitis.
- Once healed, postinflammatory hyperpigmentation and scarring may occur.
How do clinical features vary in differing types of skin?
Pseudofolliculitis barbae is more common in those with darkly pigmented skin. It is also more likely to occur in those with curly and coarse hair.
What are the complications of pseudofolliculitis barbae?
- Folliculitis barbae
- Abscess
- Postinflammatory hyperpigmentation
- Scarring including keloid scarring
Pseudofolliculitis barbae
How is pseudofolliculitis barbae diagnosed?
Pseudofolliculitis barbae is a clinical diagnosis. Dermoscopy may be used as an aid to visualise ingrown hairs and exclude differential diagnoses.
What is the differential diagnosis for pseudofolliculitis barbae?
- Folliculitis barbae
- Tinea barbae
- Acne vulgaris
- Folliculitis keloidalis (keloidalis nuchae)
- Cutaneous sarcoidosis
What is the treatment and prevention for pseudofolliculitis barbae?
The safest and most definitive cure is to discontinue shaving activity, thus patients should have the cause of PFB clearly explained to them. This may be unsuitable for many (eg, work, cultural, or personal reasons). If shaving is discontinued, it may take several weeks for the inflammatory response to cease (whilst hairs regrow).
General measures
- Ensure proper shaving technique or trialling different techniques to find which suits best. It may also be beneficial to:
- Shave in the direction of the follicle, not against it
- Do not stretch the skin
- Use short strokes
- Use sharp blades
- Avoid shaving in the same area twice (leave approx. 1 mm of stubble)
- Shave with the non-shaving hand behind the back (to reduce the temptation to make the skin taught, and thereby producing an extra close shave).
- Trial switching from a blade razor to an electric shaver.
- Reduce shaving activity e.g. only every other day.
- Consider alternative hair removal techniques eg, laser therapy.
- Ensure skin is well moisturised — preparations containing glycolic acid can exfoliate the skin surface and reduce the risk of new inflamed spots.
Specific measures
- A topical steroid cream and/or topical antimicrobials (e.g., clindamycin, erythromycin) can reduce mild inflammation and itching.
- Topical acne treatments such as benzoyl peroxide and tretinoin are used to suppress follicular hyperkeratosis.
- Oral antibiotics such as tetracyclines may reduce inflammation.
- 10 minute compresses of warm water, saline, or burrows solution (aqueous solution of aluminum acetate) can help soothe the area and remove crusts.
- Chemical depilatories can help prevent PFB such as barium sulfide paste and calcium thioglycolate; these can be irritating.
- Photodynamic therapy.
- Laser epilation (Nd YAG).
What is the outcome for pseudofolliculitis barbae?
Pseudofolliculitis barbae subsides approximately 4–6 weeks following cessation of the causative hair removal technique (most often shaving). The likelihood of experiencing further razor bumps can be reduced by trialling a different hair removal technique.
If no change is made, the condition will likely persist. Complications such as infection or scarring may arise and further treatment may be required.