Hot Tub Rash (Pseudomonas Folliculitis): Causes, Symptoms, and Treatment

Pseudomonas folliculitis ("hot tub rash") is a self-limiting bacterial skin infection caused by Pseudomonas aeruginosa, thriving in poorly maintained warm water.

Cause

Inadequate sanitation—low chlorine/bromine levels, improper pH (optimal 7.2–7.8), or contaminated filters—allows P. aeruginosa to proliferate in hot tubs, whirlpools, and heated pools.

Clinical Features

• Rash: Pruritic, erythematous papules and pustules (2–10 mm) on areas covered by swimwear (trunk, buttocks, thighs).
• Onset: 8–48 hours post-exposure.
• Systemic symptoms (mild): Low-grade fever, malaise, headache, sore throat, lymphadenopathy.
• Duration: Typically resolves in 7–14 days without scarring.

Diagnosis

Clinical, based on history of hot tub use and characteristic rash. Culture of pustule fluid confirms P. aeruginosa if needed.

Management

• Supportive: Cool compresses, antipruritics (oral antihistamines, topical corticosteroids).
• Antibiotics: Usually unnecessary. For extensive/severe cases or immunocompromised patients: oral ciprofloxacin 500 mg BID × 5–7 days (check local resistance patterns).
• Avoid: Scratching (risk of secondary infection), re-exposure until facility remediation.

Prevention

• Maintain proper disinfectant (free chlorine 3–10 ppm / bromine 4–8 ppm) and pH.
• Shower with soap before and after use.
• Remove swimwear promptly; wash thoroughly.
• Avoid hot tubs if immunocompromised or with open wounds.

Report suspected outbreaks to local health authorities. Hot tub folliculitis is distinct from Staphylococcus folliculitis and does not indicate poor personal hygiene.