How can you tell if it is lice? - briefly
Examine the scalp and hair for small, oval nits that are firmly attached within a millimeter of the skin and cannot be easily brushed off. Live lice appear as grayish, mobile insects about 2–3 mm long that move quickly when the hair is disturbed.
How can you tell if it is lice? - in detail
Lice infestation can be confirmed by a systematic visual examination of the scalp and hair. Begin by parting the hair close to the scalp in sections of about two inches. Use a fine-toothed comb, preferably a lice comb with metal teeth spaced 0.2 mm apart, and pull each section through while maintaining tension. The comb should be cleaned after each pass to prevent cross‑contamination.
Key indicators to look for:
- Live insects: Adult lice are about 2–4 mm long, grayish‑brown, and move quickly when disturbed. Nymphs are smaller, translucent, and less active.
- Nits: Oval, white or yellowish ovals attached firmly to the hair shaft within ¼ inch of the scalp. Viable nits are cemented at an angle, making them difficult to slide off the hair. Empty shells appear translucent and may be loose.
- Scalp irritation: Redness, itching, or small sores caused by bites. Persistent scratching can lead to secondary infection.
Distinguishing lice from other scalp conditions:
- Dandruff or dry skin: Flakes are loose, not affixed to the hair shaft, and lack the characteristic cemented eggs.
- Seborrheic dermatitis: Presents with greasy yellow scales and inflammation but no mobile insects or firmly attached eggs.
- Mites (e.g., scabies): Cause burrows in the skin rather than eggs on hair; lesions are typically found in interdigital spaces and wrists.
If any live insects or firmly attached nits are observed, the presence of lice is confirmed. For ambiguous cases, collect a small sample of hair with suspected nits and examine it under magnification (10× to 20×). Viable nits will show a defined operculum at one end and a darker interior, whereas empty shells appear clear and lack internal contents.
When an infestation is identified, immediate treatment should follow, using a pediculicide approved for the age group involved, and repeat the process after seven days to eliminate any newly hatched nymphs. Thorough cleaning of personal items—combs, brushes, hats, bedding—by soaking in hot water (≥50 °C) or sealing in a plastic bag for 48 hours prevents re‑infestation. Regular inspections for two weeks after treatment verify successful eradication.