Discussion
Infectious etiologies of folliculitis include bacteria, fungi, parasites, and viruses. Staphylococcus aureus is the most common infectious etiology of folliculitis. Gram negative folliculitis due toPseudomonas aeruginosa, or “hot tub folliculitis,” occurs after exposure to contaminated water from swimming pools or hot tubs. Less commonly recognized exposures include bath sponges, diving suits, and cleaning gloves. Medications such as oral contraceptives, lithium, corticosteroids, immunosuppressants, and anticonvulsants can cause non-infectious superficial folliculitis.
Superficial folliculitis is treated with cleaning the area twice daily with warm water and antibacterial soap and warm compresses. Deep or recurrent episodes of folliculitis are treated with dicloxacillin or cefalexin. Coverage for Methicillin resistant Staphylococcus aureus (MRSA) should be considered if there is purulence, signs of systemic infection, or risk factors for MRSA. Incision and drainage is recommended for larger pustules or abscesses. Untreated severe or recurrent folliculitis can lead to hair loss and scarring.
While folliculitis due to Pseudomonas aeruginosa has been well described, sepsis due to Pseudomonas folliculitis in an immunocompetent patient is rare and contributed to the diagnostic challenge in our patient. Additionally, discrepancy between Gram stain and culture results led to delay in initiating gram-negative antimicrobial coverage. Discrepancy between Gram stain and culture results occurs in 0.4% - 2.7% of cases. Interpretation of Gram stain results are subject to technician error depending on training level and experience. Recognition of potential lab error in Gram stain results is important when caring for a patient who is not responding to treatment.