What is fungal acne?

Fungal Acne: Diagnosis and Management

Fungal acne, properly known as Pityrosporum folliculitis (PF) or Malassezia folliculitis, is a fungal acneiform condition caused by overgrowth of Malassezia yeast in hair follicles, commonly misdiagnosed as acne vulgaris. Treatment with antifungal medications rather than traditional acne treatments is essential for successful management of this condition 1.

Clinical Characteristics

Presentation

• Demographics: Most commonly affects young adults (average age 24 years), with males representing approximately 64% of cases 1
• Appearance: Monomorphic 1-2mm papules and pustules 2
• Distribution: Predominantly on the:
  • Chest (70% of cases)
  • Back and shoulders (69% of cases)
  • Face, particularly forehead extending into hairline
  • Upper arms 1, 2
• Key distinguishing feature: Pruritus (itching) reported in 71.7% of cases 1

Diagnostic Clues

• Pruritic eruption that worsens with traditional acne treatments
• History of recent antibiotic use (>75% of cases) 2
• Monomorphic appearance of lesions
• Distribution pattern different from typical acne (more truncal involvement)
• Lack of comedones (blackheads/whiteheads) which are typical in acne vulgaris 3

Diagnosis

Definitive diagnosis requires:

• Skin scrapings collected with blunt scalpel or tape stripping
• KOH preparation (10-30% potassium hydroxide) showing characteristic spores consistent with yeast 4, 2
• This simple test can prevent years of ineffective acne treatment 5

Treatment

First-line Treatment

• Topical antifungals:
  • Ketoconazole 2% shampoo or cream applied daily for 2 weeks 4, 2
  • Success rate of approximately 81.6% 1

For Extensive or Resistant Cases

• Oral antifungals (success rate of 92%) 1:
  • Fluconazole
  • Itraconazole
  • Ketoconazole 4

Important Management Considerations

1. Many patients (40.5%) report history of unsuccessful treatment with traditional acne medications 1
2. Patients may have concurrent acne vulgaris and fungal acne, requiring combination therapy 5
3. Dramatic improvement is typically seen with appropriate antifungal therapy 3
4. Repigmentation of affected areas may take months after successful treatment 4

Prevention of Recurrence

• Document environmental factors contributing to recurrence:
  • High humidity
  • Excessive sweating
  • Occlusive clothing 4
• Consider prophylactic therapy for patients with frequent recurrences
• Patient education about the chronic nature of the condition and high recurrence rate 4

Common Pitfalls

1. Misdiagnosis as acne vulgaris, leading to ineffective treatment and frustration
2. Failure to perform KOH preparation when suspecting fungal acne
3. Treating with antibiotics, which may worsen the condition by altering normal skin flora
4. Not addressing concurrent acne vulgaris when present alongside fungal acne
5. Discontinuing treatment too early before achieving mycological cure

By recognizing the distinctive features of fungal acne and implementing appropriate antifungal therapy, clinicians can effectively manage this commonly misdiagnosed condition and significantly improve patients' quality of life.