Follicular Occlusion Syndrome

Key Points
Group of inflammatory skin diseases affecting the hair follicles
Exact cause is unknown, but can be due to genetic, hormonal and environmental influences
Presentation of symptoms is dependent on the subtype of the condition

Follicular occlusion syndrome is a group of inflammatory skin disorders in which hair follicles become blocked by keratin and rupture. There are four subtypes. Subtypes may coexist, and all forms of the condition may be severe and potentially hard to treat. The four subtypes are as follows:

Hidradenitis suppurativa (consists of painful lumps with sinus tracts affecting the armpits, groin, genitals, buttocks, and skin under the breasts)
Acne conglobata (consists of connected abscesses and sinuses in the affected area, filled with pus)
Dissecting cellulitis (scalp condition consisting of large nodules and cysts filled with pus that leads to scarring and Hair loss)
Pilonidal sinus (sinus tract forming at the base of the spine which fills with skin cells and hair shafts, which may become infected)

Hidradenitis Suppurativa is a fairly common disorder causing sinus tract formation with draining nodules in the intertriginous areas such as the armpit or groin. It involves occlusion of the apocrine glands, which are found primarily in these areas. It is more common in women, often presenting after puberty, and is more more severe in smokers and those suffering from obesity. Acne conglobata is a form of nodulocystic acne and can affect anyone. Dissecting Folliculitis can also affect anyone. Pilonidal sinuses are much more common in women, and those suffering from obesity are more vulnerable to its development.

Differential Diagnosis (Other conditions with similar appearance)

Hidradenitis
Actinomycosis
Granuloma inguinale (Donovanosis)
Catscratch disease
Lymphogranuloma venereum
Cutaneous Blastomycosis
Nocardia infection
Noduloulcerative Syphilis
Cutaneous Crohn’s disease

Diagnosis
Key Points
Diagnosis based on appearance of the affected area most commonly
Skin biopsy and other testing may be performed to rule out similar appearing conditions

Follicular occlusion syndromes are generally diagnosed based on appearance of the affected area. Biopsies of the affected area, along with other testing, may be performed to rule out other, similar-appearing conditions.

Treatment
Treatment depends on the condition subtype
Goal of treatment is to control and reduce symptoms
In many cases, treatment consists of administration of antibiotics or steroids

Treatment of follicular occlusion syndromes is dependent on the subtype condition, but often involves the administration of Antibiotics and/or steroids. In Hidradenitis suppurativa, treatment consists of the use of antiseptics and antibiotics in conjunction with retinoids, corticosteroids, and in some cases surgery. Acne conglobata is generally treated with Antibiotics, Isotretinoin, and systemic corticosteroids over a prolonged time period. Dissecting Folliculitis is very resistant to any treatment, but the severity of symptoms may be alleviated with orally administered Isotretinoin, antibiotics, Dapsone and steroid Injections. In mild cases of pilonidal sinuses, treatment may not be necessary and the condition may resolve spontaneously. In cases of chronic inflammation or infection, antibiotics and surgical repair may be required.