Head lice

Head pediculosis (synonyms: pediculosis, lice) is a disease caused by head louse that parasitizes on the scalp and neck.

[1], [2], [3], [4], [5], [6], [7], [8]

Causes and pathogenesis of head lice

The head louse (pediculus humanus capitis) is 2-3.5 mm in length and is a grayish white specimen. Preferably affects children and people with long hair. Transmission occurs from person to person through headgear or comb. Inadequate hygiene and life in crowded communities contribute to its spread. Often small endemics develop in schools. Outside the host, the head louse can live 55 hours. Unlike a louse, the head louse is not a carrier of infections.

[9], [10], [11], [12], [13], [14]

Symptoms of head lice

The main place of localization is the head. The hair on the beard and pubis are rarely affected. On the scalp, the area behind the ears is most often affected. Head lice absorb blood by biting every 2-3 hours. Skin manifestations become noticeable only after a few hours or days. In this case, bright red urticaria papules develop, which because of the penetration of the saliva of the lice are very itchy. On the nape often there is a typical eczema of lousy. Brushing often leads to secondary bacterial infections, and, finally, to strong tangling of hair and the formation of a knuckle (trichomes). Secondary infection caused and painful lymphadenitis in the occipital region and in the neck with a tendency to abscessing.

Diagnosis of head lice

It is placed on the basis of a typical clinic when proving the presence of lice. Strong itching of the lice can cause even small amounts. If there are no lice, then they are looking for nits - they are kidney-shaped, glued to the hair, oval, 0,8 mm long, lice eggs, hidden in a chitinous shell. At first they sit at the base of the hair, and with the growth of the hair they move to its tip and by this time are most often empty: there is no lining of the nit. Unlike dandruff, nits do not roll off hair, but sit firmly. Places of preferred location - areas behind the ears. On examination, it is necessary to raise the hair on the side above the ears to detect nits there. Lice can not be found. Itching of the head, eczema of the head and occiput with impetiginization should lead the doctor to the idea of head lice.

[15], [16], [17], [18], [19], [20]

Differential diagnosis

Eczema head, contagious impetigo, psoriasis of the scalp.

[21], [22], [23], [24], [25], [26], [27], [28], [29], [30]

Treatment of head lice

It is necessary to destroy not only lice, but also their embryos in nits.

Lindane (gamma-hexachlorocyclohexane) is used as a 0.3% gel. The hair is washed with shampoo, then the gel is rubbed into wet hair and repeated carefully combed. This requires about 15 g of gel. The gel should stay in the hair for three days, then wash the head. With this treatment, nits also die and are removed by rinsing with a warm vinegar solution (1 part 6% food vinegar to 2 parts water) and then combing with a frequent comb. During pregnancy and feeding, lindane is contraindicated, but it is permissible for infants and preschool children.

Para-Plus (permethrin + malathion). It is used as a spray and also acts on lice and nits. The drug is sprayed from a distance of 1-2 cm, by pressing for 1-2 seconds, the sprayer is covered from the outside with a hand. It is important to carefully treat the entire base of the hair, including the whiskey and the back of the head. After 320 minutes, hair is washed with a normal shampoo, then rinsed with acetic water and combed, as indicated above. A week later, a follow-up check is performed, with repeated growth of lice or nits, the treatment is repeated. Shawls and hats can be sprayed from a distance of 20 cm. The drug is contraindicated during pregnancy and feeding. Apply it only in large, well ventilated areas. It should pay attention to its special toxicity for the cold-blooded: terrarium, aquarium.

Malathion (0.5% solution). This solution (flammable!) Completely covers the hair and scalp (10-20 ml). After drying in air (without a hair dryer!) And 12 hours of action, the hair is thoroughly washed with shampoo. Follow up after 8-10 days. Malathion is absorbed by keratin and therefore should have a certain protective effect for several weeks. It is contraindicated in infants.

Permethrin (1% cream rinse) is rubbed into damp washed hair and washed off after 30 minutes. The treatment of infants and preschool children is carried out under the supervision of a doctor.

Prevention of head lice

All persons who have come into contact with patients (family, kindergarten, school, nursing home) should be examined and, if necessary, treated. Often there are small endemics.