Folliculitis decalvans

Folliculitis decalvans is an inflammation of the hair follicle that leads to bogginess or induration of involved parts of the scalp along with pustules, erosions, crusts, and scale.^{[1]:649[2]:760-1} It begins at a central point and spreads outward, leaving scarring, sores, and, due to the inflammation, hair loss in its wake.^[3] No permanent cure has been found for this condition. But there is promise in a regimen of dual therapy with Rifampin 300 mg twice daily and Clindamycin 300 mg twice daily. This new treatment can be used to control the condition, and tests have indicated that after 3 to 5 months long uninterrupted courses of treatment, many patients have seen limited to no recurrence.^[4]

Introduction and epidemiology

This disorder was first described by Charles-Eugène Quinquaud in 1888. He isolated bacteria from the hair follicles of affected patients and introduced them in rats, mice and rabbits, with no result. In 1905 it was then differentiated from other scarring alopecias and the name Follicuilitis decalvans, that remains current, was introduced. About 11% of the occurrences of scarring alopecias are of this type. Men are more commonly affected than women and its appearance is usually between the late teens and middle adult years. According to studies in the United States, African Americans are more frequently affected than White Americans.

Causes

There is no certainty about the cause of this disorder, but it is known that the bacteria Staphylococcus aureus has a central role. This bacteria can be detected in the lesions of most patients. It is unclear if a primarily sterile infection with secondary colonization by Staphylococcus aureus is present, or if this bactery itself leads at first to a strong immune reaction. Another possibility is that the toxins produced by this bacteria could act as superantigens that activate directly the T-cells over the variable domain of t-cell receptors. Nonetheless Staphylococcus aureus can by found in almost all patients affected by this disorder, while it is only seen in 20-30% of non-affected people.

As Staphylococcus aureus is not always found in people that suffer from Folliculitis decalvans, other factors must be present. Through examinations in families it was found that there is a family connection to the occurrences, which leads to the conclusion that there is a genetic predisposition for it, for example, patients with Folliculitis decalvans could have a hereditary different opening of the hair follicle, that could facilitate the lodging of the bacteria. Immunologically, another possibility is that specially strong intercellular fixation protein ICAM-1 contributes to numerous inflammations with its strong effect of attracting neutrophiles such as granulocytes and lymphocytes.

See also

• Cicatricial alopecia

References