# Folliculitis Decalvans and Dissecting Cellulitis

> Folliculitis decalvans and dissecting cellulitis for NEET-PG Dermatology covers neutrophilic scarring, tufted hairs, antibiotic combinations and isotretinoin.

- Canonical URL: https://prepelephant.com/topics/neet-pg/dermatology/folliculitis-decalvans-and-dissecting-cellulitis
- Exam / course: NEET-PG · Subject: Dermatology
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-15
- Last updated: 2026-10-15
- Reference basis: Fitzpatrick's Dermatology; Rook's Textbook of Dermatology; IADVL Textbook of Dermatology
- How to cite: "Folliculitis Decalvans and Dissecting Cellulitis", PrepElephant, https://prepelephant.com/topics/neet-pg/dermatology/folliculitis-decalvans-and-dissecting-cellulitis

## Direct answer

Folliculitis decalvans is a neutrophilic scarring folliculitis of the scalp that destroys hair follicles in patches, usually in young and middle-aged adults. Its hallmark is tufted hairs, with several hairs emerging from one follicle surrounded by pustules and crusts. Dissecting cellulitis of the scalp is a related disorder with deep nodules, abscesses and sinus tracts, and both need early treatment because the scarring is permanent.

## What you must remember

- **Neutrophilic scarring:** folliculitis decalvans is a neutrophilic cicatricial alopecia, so scarring forms as pus-forming inflammation destroys the follicle.
- **Tufting:** several hairs emerge from a single follicular opening, a clue best seen on clinical inspection or dermoscopy.
- **Organism:** Staphylococcus aureus is commonly cultured from pustules, which is why antibiotics form a core part of treatment.
- **Dissecting cellulitis:** deep, painful nodules and abscesses on the scalp with interconnected sinus tracts, most often in men.
- **Follicular occlusion tetrad:** acne conglobata, dissecting cellulitis of the scalp, hidradenitis suppurativa and pilonidal sinus.
- **Isotretinoin:** among the most effective systemic drugs for dissecting cellulitis and used for refractory folliculitis decalvans.
- **Biopsy:** a deep punch biopsy shows a neutrophilic infiltrate around the follicle with fibrosis, which helps separate these disorders from alopecia areata.
- **Permanence:** scarring is irreversible, so early control of inflammation protects the remaining hair.

## A stepwise ladder for scalp folliculitis

Management follows a graded ladder, because most patients need more than one agent and early escalation limits scarring. The steps below reflect common dermatology practice for chronic scarring scalp folliculitis.

1. **Confirm the diagnosis:** combine tufting, pustules and crusts with a biopsy, and send pus for culture where infection is suspected.
2. **Start oral antibiotics:** long-course combinations such as rifampicin with clindamycin are widely used, and tetracyclines are alternatives. Rifampicin lowers the effect of oral contraceptives, so counselling is essential.
3. **Add topical therapy:** topical clindamycin or antiseptic washes reduce surface bacteria while systemic treatment works.
4. **Use intralesional steroids:** injections into active plaques or nodules reduce inflammation quickly in localised disease.
5. **Escalate to isotretinoin:** refractory folliculitis decalvans or dissecting cellulitis is treated with isotretinoin, with pregnancy prevention and lipid monitoring.
6. **Consider surgery:** established sinus tracts or recurrent abscesses may need wide excision, which is planned once the disease is quiet.

## Where the exam tries to catch you

Stems on scalp folliculitis test whether you spot permanent scarring and choose the right escalation step.

- **Trap:** labelling tufted pustules as routine bacterial folliculitis and giving a short antibiotic course. **Correct:** folliculitis decalvans is a chronic scarring disease that needs prolonged combination therapy and may need isotretinoin.
- **Trap:** diagnosing scarring alopecia as alopecia areata because of patchy hair loss. **Correct:** alopecia areata lacks pustules, crusts and tufting, and biopsy in this disease shows a neutrophilic scarring pattern.
- **Trap:** treating dissecting cellulitis with incision and drainage alone. **Correct:** drainage gives temporary relief, but isotretinoin and systemic therapy address the underlying follicular occlusion.

## Frequently asked questions

### Which antibiotic combination is commonly used for folliculitis decalvans?

Rifampicin combined with clindamycin is a widely used long-course regimen for folliculitis decalvans, because staphylococci are often implicated in the disease. Tetracyclines such as doxycycline are also used. Rifampicin needs counselling because it reduces the effect of oral contraceptives.

### What is the follicular occlusion tetrad?

The follicular occlusion tetrad groups acne conglobata, dissecting cellulitis of the scalp, hidradenitis suppurativa and pilonidal sinus. These conditions share follicular occlusion and rupture, which leads to deep inflammation and sinus formation.

### Why is isotretinoin used in dissecting cellulitis of the scalp?

Isotretinoin is among the most effective systemic drugs for dissecting cellulitis of the scalp, especially when antibiotics have failed. It reduces sebaceous activity and follicular plugging, but it needs pregnancy prevention and lipid monitoring before and during treatment.

### How does folliculitis decalvans differ from alopecia areata on biopsy?

Folliculitis decalvans shows a neutrophilic infiltrate around follicles with scarring, while alopecia areata shows a lymphocytic peribulbar infiltrate without fibrosis. Clinically, tufting, pustules and crusts favour folliculitis decalvans, and the biopsy confirms the diagnosis.