The Bottom Line

Folliculitis decalvans (FD) is a rare, chronic scarring alopecia — a type of permanent hair loss — that accounts for about 1–3% of all scarring hair loss conditions. It overwhelmingly affects men (at a 4:1 ratio over women) and is driven by ongoing bacterial infection combined with a destructive immune response. Without treatment, it progresses steadily. The earlier it is caught and treated aggressively, the more follicles can be saved.

What Is Folliculitis Decalvans?

Folliculitis decalvans is a form of suppurative (pus-forming) scarring alopecia. That means it causes permanent hair loss by destroying hair follicles through a combination of infection and inflammation. It is rare — affecting less than 0.001% of the general population — and is considered a chronic condition that requires long-term management rather than a short course of treatment.

FD predominantly affects men aged 20–50, though women and children may be affected. There is no clearly documented racial preference, but some case series suggest geographic and familial clustering, hinting at genetic predisposition. The disease is not contagious, despite its infectious component.

How Does It Damage Hair Follicles?

The destruction in FD unfolds in a specific way:

  1. Bacterial colonization: Staphylococcus aureus — the most commonly isolated bacteria — colonizes hair follicles. Sometimes methicillin-resistant strains (MRSA) are involved.
  2. Abnormal immune response: Instead of clearing the infection normally, the immune system launches a severe neutrophilic (white blood cell) attack on the follicle itself, forming abscesses around and within the follicle structure.
  3. Follicle destruction: The intense inflammation destroys the follicular stem cells in the "bulge" region — the zone responsible for hair regeneration. Once these stem cells are gone, the follicle cannot rebuild.
  4. Fibrosis: The destroyed follicle is replaced by fibrous scar tissue, and the cycle continues in adjacent follicles if not treated.

Some researchers believe FD may represent a continuum with folliculitis keloidalis nuchae (a related scarring condition at the nape of the neck), given the overlapping mechanisms.

What Are the Symptoms?

FD typically presents with:

  • Recurring pustules and follicular crusting on the scalp, most often on the vertex (top) and parietal (side) regions
  • Purulent (pus-like) drainage from involved follicles
  • Painful, tender, inflamed scalp — itching is common and sometimes severe
  • Progressive scarring that creates permanent bald patches with a characteristic appearance: shiny scarred center surrounded by active pustular margins
  • Tufted folliculitis in some cases — where several hairs emerge from a single follicular opening at the edge of active disease
  • Swollen cervical or occipital (neck and base-of-skull) lymph nodes in some patients, reflecting systemic inflammatory response

The pace of progression varies — some patients slowly worsen over years, while others experience rapid spread causing significant baldness within months.

How Is It Diagnosed?

A combination of clinical assessment, laboratory testing, and scalp biopsy establishes the diagnosis:

  • Clinical pattern: The characteristic suppurative folliculitis with scarring in typical scalp locations is highly suggestive
  • Bacterial culture and sensitivity: A swab from pustule contents identifies the organism and determines which antibiotics will work — essential for targeted therapy
  • Scalp biopsy: Shows severe neutrophilic infiltration around follicles, abscess formation, follicular destruction, and fibrosis. The predominantly neutrophilic infiltrate distinguishes FD from lymphocyte-dominant alopecias like lichen planopilaris and discoid lupus
  • Dermoscopy: Reveals pustules, erythema, follicular crusting, and a "spongy" appearance of affected scalp. Negative bacterial culture does not exclude the diagnosis — some cases may represent a sterile neutrophilic inflammation that mimics infection

Full Treatment Approach

Antimicrobial therapy (cornerstone of treatment)

  • Rifampicin + clindamycin combination — considered by many experts as the most effective regimen; rifampicin penetrates S. aureus biofilms and is synergistic with clindamycin; typically used for 10 weeks
  • Doxycycline 100 mg once or twice daily — long-term tetracycline therapy providing sustained anti-staphylococcal coverage plus anti-inflammatory effects; treatment continues until complete pustule resolution and disease stabilization (often 3–12 months)
  • Minocycline 100 mg daily — effective alternative to doxycycline with similar dual action
  • Topical clindamycin or fusidic acid — applied directly to pustular areas as an adjunct to systemic therapy

Anti-inflammatory agents

  • Systemic corticosteroids (prednisone 0.5–1 mg/kg, tapered over weeks) — used during severe flares to rapidly reduce inflammation and halt progression
  • Intralesional triamcinolone acetonide (2.5–5 mg/mL) — injected into individual active lesions to suppress local inflammation

Isotretinoin for refractory or relapsing disease

Isotretinoin (0.5–1 mg/kg/day) reduces sebaceous gland output and follicular obstruction — addressing the environment that allows bacterial overgrowth. It can produce sustained remissions in patients who cycle repeatedly through antibiotic courses. Regular blood monitoring is required during isotretinoin treatment.

Laser hair removal

In carefully selected patients, laser hair removal (typically Nd:YAG laser) permanently destroys the follicles in actively affected areas, removing the target of repeated infection. This can halt disease progression in localized zones and is increasingly used alongside systemic treatment for refractory disease.

Dapsone

Dapsone is sometimes used for its dual antibacterial and anti-neutrophilic (anti-inflammatory) effects, particularly in patients who cannot tolerate or do not respond to tetracyclines.

When to See a Dermatologist

  • You have had recurring scalp infections that do not fully resolve between antibiotic courses
  • You notice areas of the scalp becoming permanently bald with shiny, smooth skin at the center
  • Scalp pustules are progressing despite treatment
  • You have a family member with a similar chronic scalp condition
  • Standard antibiotic courses have been repeatedly prescribed without lasting improvement
  • You want a thorough evaluation including biopsy and culture to confirm the diagnosis

Frequently Asked Questions

Why does folliculitis decalvans keep coming back even after treatment?

FD tends to recur because the underlying predisposition — an abnormal immune response to S. aureus combined with possible genetic susceptibility — is not eliminated by antibiotics alone. Short courses kill the bacteria temporarily but do not change the immune environment. Long-term treatment strategies, including prolonged antibiotics and isotretinoin, are more effective at achieving durable remission.

How is folliculitis decalvans different from lichen planopilaris?

Both are scarring alopecias, but they have very different causes and microscopic patterns. FD is driven by bacterial infection and shows neutrophilic (pus-cell) inflammation on biopsy. Lichen planopilaris is autoimmune and shows lymphocytic (immune cell) inflammation targeting the follicle. The treatments are completely different — FD requires antibiotics, while LPP requires immune-modulating drugs.

Is there a risk of the disease spreading to other people in my household?

FD itself is not contagious. However, S. aureus can be carried on the skin of household members. In some families with multiple affected individuals, decolonization measures (such as mupirocin nasal ointment and chlorhexidine washes for all household members) may be recommended by your dermatologist.

What happens if I stop treatment too early?

Stopping treatment prematurely is the most common reason for relapse. In many patients, the disease appears controlled while on antibiotics but flares within weeks of stopping. Your dermatologist will advise when it is safe to taper or stop, based on clinical signs, culture results, and scalp examination — not simply based on how long you have been on treatment.

References

  1. Vano-Galvan S, et al. Folliculitis decalvans: a multicentre review of 82 patients. J Eur Acad Dermatol Venereol. 2015;29(9):1750–1757.
  2. Otberg N, et al. Folliculitis decalvans. Dermatol Ther. 2008;21(4):238–244.
  3. Sillani C, Bin Z, Ying Z, et al. Effective treatment of folliculitis decalvans using selected antimicrobial agents. Int J Dermatol. 2010;49(8):909–912.
  4. Vaño-Galván S, et al. Laser hair removal for the treatment of folliculitis decalvans: a case series. Lasers Med Sci. 2010;25(1):53–56.
  5. Brooke RC, Griffiths CE. Folliculitis decalvans. Clin Exp Dermatol. 2001;26(1):120–122.

Trusted Resources

Always consult a board-certified dermatologist for diagnosis and personalized treatment recommendations. This article is for educational purposes and does not replace professional medical advice.