Lice - Diagnosis

Doctors can often easily diagnose lice with a visual examination. The lice are large enough to be seen with the naked eye or through a magnifying glass. Brown specks on the patient's underwear are another sign of lice. The patient may also have bruised skin where he or she has been scratching. Lice nits are also easy to see. They can be found at the base of hairs near the skin.

Final diagnosis may involve ruling out other medical problems. For example, ordinary dandruff sometimes looks like an infestation of head lice. Scabies also resembles body lice. Scabies is a skin condition caused by tiny organisms called skin mites. Differences among diseases can usually be detected with a microscope. Blood and other laboratory tests are not useful in making these distinctions.