Folliculitis decalvans

What is folliculitis decalvans?

Folliculitis decalvans is achronic,neutrophilicinflammationthat results in scarringhairloss. Tufted hair folliculitis is probably a subset of folliculitis decalvans although tufting can be seen in other forms ofcicatricialalopeciaas well.

Who gets folliculitis decalvans?

Folliculitis decalvans usually presents in the 4^thand 5^thdecades, with a male predominance. Children are not affected.

There are probably no racial differences inprevalence, although it has been claimed to be more common in African-American women.

Familialcases have been rarely reported.

What causes folliculitis decalvans?

Folliculitis decalvans is considered to be the result of an abnormal immune response toStaphylococcus aureus, although this is not yet proven.

What are the clinical features of folliculitis decalvans?

Folliculitis decalvans typically affects the scalp, often around the crown, but may affect the beard area,axillae, limbs, and pubic hair. The characteristic clinical features include:

• Irregular,atrophicwhite patches of scarring and hair loss — solitary or multiple
• Indurationof the scalp
• Follicularpustulesandperifollicularcrusts at thepatchperiphery
• Follicularhyperkeratosis,scale, anderosions
• Tufting — multiple hair shafts emerge from a single hairfollicle, resulting in a ‘doll’s hair’ appearance
• Mild itch, discomfort, or pain.

Perifollicular crusting and scale

簇毛和perifollicular crusting

簇毛和perifollicular erythema

Dermoscopyof folliculitis decalvans

• Tufted hairs
• White dots
• Perifollicularerythemaand scale
• Scattered follicular pustules

What are the complications of folliculitis decalvans?

• Permanentprogressivehair loss
• Psychological effects of hair loss
• Squamouscellcarcinoma

How is folliculitis decalvans diagnosed?

Folliculitis decalvans is a clinical diagnosis confirmed onbacteriology/mycologyandhistologyif required.

Skinbiopsyof an earlylesionshows a neutrophilicinfiltratedilating theinfundibulumof the hair follicle. The follicle in laterlesionshas ruptured resulting in perifollicular scarring and mixedinflammatoryinfiltrate including foreign bodygiant cells.

What is thedifferential diagnosisfor folliculitis decalvans?

• Tinea capitis
• Perifolliculitiscapitis abscedens et suffodiens
• Other causes of cicatricial alopecia includingdiscoid红斑狼疮andlichen planopilaris

What is the treatment for folliculitis decalvans?

General measures

• Topicalantiseptics and shampoos — although little evidence forefficacy

Specific measures

• Antibiotics
  • Topical such asfusidic acid
  • Oraltetracyclines, azithromycin,rifampicinin combination withclindamycin
• Othersystemicagents (off-label)
  • Oralisotretinoin,dapsone,tacrolimus,apremilast
  • Intravenousimmunoglobulin,tumournecrosisfactorinhibitors
• Physical therapies
  • Photodynamictherapy
  • Surgeryfor permanent hair loss if inremission

What is the outcome for folliculitis decalvans?

Folliculitis decalvans usually follows a chronic fluctuating course ofexacerbationsandremissionsover many years. It is not clear that treatment influences the long-termprognosisdespite successfully reducing inflammation in the short-term. Early diagnosis and treatment are important but permanent hair loss is to be expected.