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Phthiriasis: causes, symptoms, diagnosis, treatment
Last reviewed: 20.11.2021
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Fthiaz (synonyms: pubic pediculosis, carpels, phthiriasis) is a disease caused by pubic lice that live mainly on the pubis, sometimes on the chest, underarms, eyelashes of the upper eyelids.
Causes of fthiracy
The pubic louse (pediculus pubis or phthirus pubis, carpenter) is 1.5-2 mm shorter than the head and body, has a wider thyroid shape. The second and third pairs of legs end in pronounced claws, through which the louse is held at the base of the hair. Pubic lice, unlike other species, almost do not move, so they are more difficult to recognize. They also reproduce more slowly. It is easier to find their nits.
Transmission is carried out in close physical contact, most often with sexual intercourse, as well as from parents to children. Perhaps spread through clothing, bedding or towels.
Symptoms of phthyroidism
Favorite places of localization of this type of lice are areas with apocrine sweat glands: pubis, genito-anal area, axillary hollows, and also, with thick hair, chest and abdomen. Less often, and more often in young children, they are found in the scalp, on the eyebrows and eyelashes. Itching with pubic lice is moderate, but increases at night. The effects of scratching are usually absent. As a consequence of bites of pubic lice, a blurred steel blue or gray hue of a spot, up to the size of the nail - maculae coeruleae - appears in typical localization sites. Their origin is probably related to the intradermal deposition of greenish decomposition products of hemoglobin, which occurs under the influence of saliva in lice. With severe itching, secondary changes are noted in the form of excoriations, impetigo, lichenization. Children may have lashes and eyebrows in the form of serous crusts, and in some cases, edema of the eyelids.
Diagnosis of fthiroid
Cyanotic blue spots (Maculae coeruleae) with typical localization, especially in the lower abdomen or on the hips are important diagnostic features. Proof is the presence of lice or their nits. When patients complain of itching in the genital area or armpits, one should take into account the possibility of pubic lice.
Treatment of fthiroid
It is carried out in the same way as with head lice, with the use of lindane, allethrin, piperonyl butoxide and pyrethrium extract. With thick hair on the body, these places also require treatment along with the area of the pubis and axillae. It is important to examine and treat patients who have been in contact with the patient.
Treatment for lesions of eyebrows and eyelashes in children presents difficulties, since the above preparations can, due to toxic irritation, cause conjunctivitis. If possible, use forceps to remove lice from the eyelashes. For local treatment, a simple white petrolatum 5% aqueous solution of malathion is recommended, and 1% yellow mercury ointment is applied under the bandage to the edge of the eyelids 2 times a day for 7-10 days.
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