Illness script
Folliculitis
Superficial hair-follicle inflammation causing itchy or tender follicular pustules and papules on hair-bearing skin.
This illness script for Folliculitis covers the classic presentation, who it affects, how you work it up, the mechanism, and first-line treatment—written for USMLE Step 1 and clerkship clinical reasoning.
Updated Jul 18, 2026All scripts
01
Who it affects
- Any age; common in adolescents and young adults
- Risk: shaving, occlusion, sweating, tight clothing
- Hot tub/pool exposure (Pseudomonas)
- Diabetes, obesity, immunosuppression, topical steroid use
- Long-term antibiotics predispose to gram-negative folliculitis
02
Diagnostics & workup
- Clinical diagnosis: pustules/papules centered on hair follicles
- Most commonly Staphylococcus aureus
- Hot tub folliculitis: Pseudomonas, appears 1-2 days post-exposure
- KOH prep if fungal (Malassezia/dermatophyte) suspected
- Bacterial culture/Gram stain for recurrent or resistant cases
- Consider biopsy for atypical or refractory lesions
03
Pathophysiology
- Infection or inflammation of the hair follicle ostium
- S. aureus enters via minor trauma (shaving, friction)
- Pseudomonas from contaminated warm water penetrates follicles
- Occlusion and moisture promote microbial overgrowth
- Malassezia folliculitis: yeast overgrowth in sebaceous follicles
04
Treatment
- Mild: warm compresses, antibacterial washes (chlorhexidine, benzoyl peroxide)
- Topical clindamycin or mupirocin for localized bacterial cases
- Oral antistaphylococcal antibiotics (cephalexin, dicloxacillin) if extensive
- Hot tub folliculitis: usually self-limited, resolves without treatment
- Malassezia: topical/oral antifungals (ketoconazole, itraconazole)
- Prevent: avoid shaving irritation, reduce occlusion, treat carriers with intranasal mupirocin
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Educational use only. This illness script is a study framework, not medical advice. Confirm decisions with current guidelines and your clinical supervisors.