Folliculitis

Folliculitis is the name given to a group of skin conditions in which there are inflamed hair follicles. The result is a tender red spot, often with a surface pustule. Folliculitis can be due to infection, occlusion, irritation and specific skin diseases.

Folliculitis may be superficial or deep.

Folliculitis

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Infection

To determine if folliculitis is due to an infection, swabs should be taken from the pustules for culture in the laboratory.

Bacteria
Bacterial folliculitis is commonly due to Staphylococcus aureus. If the infection involves the deep part of the follicle, it results in a painful boil. Recommended treatment includes careful hygiene, antiseptic cleanser or cream, antibiotic ointment, and / or oral antibiotics.

Spa pool folliculitis is due to infection with Pseudomonas aeruginosa, which thrives in inadequately chlorinated warm water. Gram negative folliculitis is a pustular facial eruption also due to infection with Pseudomonas aeruginosa or other similar organisms. It usually follows tetracycline treatment of acne and is quite rare.

Yeasts
The most common yeast to cause a folliculitis is Pityrosporum ovale, also known as Malassezia. Malassezia folliculitis (Pityrosporum folliculitis) is an itchy acne-like condition usually affecting the upper trunk of a young adult. Treatment includes avoiding moisturisers, stopping antibiotics and topical antifungal or oral antifungal medication for several weeks.

Fungi
Ringworm of the scalp (tinea capitis) usually results in scaling and hair loss, but sometimes results in folliculitis. In New Zealand, cat ringworm (Microsporum canis) is the commonest organism causing scalp fungal infection. Other organisms such as Trichophyton tonsurans are increasingly reported. Treatment, which requires a doctor's prescription, is with oral antifungal agents for several months.

Irritation from regrowing hairs

Folliculitis may arise as hairs regrow after shaving, waxing, electrolysis or plucking. Swabs taken from the pustules are sterile i.e. there is no growth of bacteria or other organisms.

In the beard area irritant folliculitis is known as pseudofolliculitis barbae.

Irritant folliculitis is also common on the lower legs of women. It is frequently very itchy. You must stop removing the hairs. Do not recommence for about three months after the folliculitis has settled. A lady's electric razor is the gentlest way to remove hair from the limbs.

Contact reactions

Occlusion
Paraffin-based ointments, moisturisers, and adhesive plasters may all result in a sterile folliculitis. If a moisturiser is needed, choose an oil-free product.

Chemicals
Coal tar, cutting oils and other chemicals may cause an irritant folliculitis. Avoid contact with the causative product.

Topical steroids
Overuse of topical steroids may produce a folliculitis. Perioral dermatitis is a facial folliculitis provoked by moisturisers and topical steroids. Perioral dermatitis is treated with tetracycline antibiotics for six weeks or so.

Inflammatory skin diseases

Certain uncommon inflammatory skin diseases may cause permanent hair loss and scarring because of deep seated sterile folliculitis. These include lichen planus, discoid lupus erythematosus and folliculitis decalvans. Treatment depends on the underlying condition and its severity. A skin biopsy is often necessary to establish the diagnosis.

Immunosuppression

Eosinophilic folliculitis may arise in some immune suppressed individuals such as those infected by human immunodeficiency virus (HIV). Its cause is not yet understood.

Acne variants

These include acne vulgaris, nodulocystic acne, steroid acne, rosacea, proprionibacterium folliculitis, acne necrotica, chloracne, and acne keloidalis nuchae (folliculitis keloidalis).

The follicular occlusion syndrome refers to hidradenitis suppurativa (acne inversa), acne conglobata (a severe form of nodulocystic acne), dissecting cellulitis (perifolliculitis capitis abscedens et suffodiens) and pilonidal sinus.

Treatment of the acne variants may include topical therapy as well as long courses of tetracycline antibiotics, isotretinoin (vitamin-a derivative) and in women, antiandrogenic therapy.