B36.3

Clinical Causes: Infection by the fungus Piedraia hortae, which preferentially grows on hair shafts Poor hygiene or infrequent hair washing, creating moist environments conducive to fungal growth Use of contaminated grooming tools or hair accessories Living in humid climates or areas with high moisture levels Sharing hairstyles, hats, or pillows that may harbor fungal spores Underlying scalp conditions or compromised immune status that facilitate fungal colonization

Key Symptoms: Hard, darkly pigmented nodules or concretions attached to hair shafts, often black or dark brown in color Localized scalp or hair shaft brittleness and breakage Minimal or no itching; symptoms are primarily cosmetic Possible mild scalp discomfort or irritation in some cases Unusual hair texture or appearance due to fungal growth Occasional scalp odor if secondary bacterial infection occurs

Diagnosis Path: Clinical examination revealing characteristic black nodules attached to hair shafts Microscopic examination of hair samples to identify fungal structures Wood's lamp examination is generally not helpful as the fungi do not fluoresce Hair pull or pluck test to assess the extent of fungal involvement Possibility of fungal culture or biopsies if diagnosis remains uncertain

Treatment Protocols: Topical antifungal agents such as selenium sulfide shampoos or ketoconazole shampoo applied regularly to affected areas Manual removal of visible nodules and fungal debris through gentle grooming Maintaining good scalp hygiene to prevent re-infection In some cases, oral antifungal medications may be prescribed for extensive or persistent infections Avoiding shared grooming tools and personal items to reduce spread Improving environmental conditions, such as reducing humidity and ensuring proper hair care practices