Understanding Lice and Scabies -- Symptoms

Medically Reviewed by Debra Jaliman, MD on September 14, 2023
2 min read
  • Head lice: intense itching on the scalp, especially behind the ears and at the nape of the neck. Sores may develop as a result of scratching. Symptoms may not occur for four to six weeks. Some people may have no symptoms.
  • Body lice: intense itching and rash. Sores may develop as a result of scratching.
  • Pubic lice: continual itching around the pubic and groin area. Sores may develop as a result of scratching. Those infested with pubic lice may also have other sexually transmitted diseases since this infestation is often the result of close contact with an infested person.
  • If this is the first infestation, symptoms may not appear for up to two months, but a person can still spread scabies even without symptoms.
  • Intensely itchy rash with red patches generally located between the fingers, around the wrists, and on the elbows, navel, nipples, buttocks, lower abdomen, and genitals. The face and scalp are rarely affected in adults but may be involved in small children.
  • Lesions as thin as pencil lead that mark where the scabies mites have burrowed into the skin; these are visible in only about 25% of cases.

Since the distinguishing burrow tunnels are difficult to see, you may have to rely on other signals to determine whether you have been infested. People with flaking skin disorders, such as eczema and psoriasis, need to be especially vigilant. Because they already tend to have itchy, red skin, they may not notice symptoms until the infestation is widespread.

A severe form of scabies, known as crusted scabies, can cause blisters, thick crusts on the skin that may not itch, and thickened nails. Crusted scabies is usually seen in the elderly, debilitated, disabled, or those with a weakened immune system