If it's not lice, what could it be? - briefly
It could be dandruff, seborrheic dermatitis, hair casts, or another type of scalp debris that mimics an infestation. A professional examination will distinguish these conditions from actual lice.
If it's not lice, what could it be? - in detail
When an examination of the scalp reveals small, moving organisms or irritant particles, and lice are excluded, the clinician must consider several alternative etiologies.
The most common non‑lice conditions include:
- Dermatophytic infection (tinea capitis). Presents with scaling, patchy hair loss, and sometimes inflamed pustules. Microscopic examination shows hyphae rather than arthropods. Oral antifungal therapy resolves the infection.
- Seborrheic dermatitis. Characterized by greasy, yellowish flakes and erythema. No live insects are observed; only excess sebum and Malassezia yeast proliferation. Topical antifungal or keratolytic agents provide relief.
- Allergic contact dermatitis. Triggered by hair products, dyes, or shampoos. Symptoms consist of itching, redness, and sometimes vesicles. Patch testing identifies the allergen, and avoidance plus corticosteroid creams reduce inflammation.
- Scabies infestation. Mite burrows appear as tiny, linear tracks on the scalp, often accompanied by intense nocturnal itching. Skin scraping reveals Sarcoptes scabiei, and systemic ivermectin or topical permethrin is required.
- Pediculosis from other insects. Certain species, such as Pthirus pubis (pubic lice) or bird lice, may temporarily colonize hair. Morphology differs from head lice; identification under magnification guides appropriate treatment with specific pediculicides.
- Hair cast (pseudonits). Cylindrical, translucent sleeves cling to hair shafts, mimicking nits. They are composed of keratin debris, not eggs. Gentle combing removes them; no medication is needed.
- Molluscum contagiosum. Small, dome‑shaped papules with a central dimple may be mistaken for lice eggs. Histology shows viral inclusions; curettage or topical agents eradicate lesions.
Diagnostic steps:
- Visual inspection with a fine‑toothed comb to collect specimens.
- Microscopic analysis to differentiate eggs, larvae, fungal hyphae, or mite parts.
- Culture or PCR when fungal or viral agents are suspected.
- Allergy testing if contact dermatitis is probable.
Treatment selection depends on the identified cause, with antifungals for fungal disease, corticosteroids for dermatitis, pediculicides for lice‑like insects, and antiparasitic drugs for scabies. Accurate identification eliminates unnecessary pesticide use and directs effective therapy.