Scabies

Scabies is an infestation of the skin by a tiny mite called Sarcoptes scabiei, far too small to see with the naked eye. The female mite burrows into the top layer of the skin and lays her eggs there. The intense itching that follows is not caused by the mite biting, but by the body reacting to the mite, its eggs and its waste. The itch is classically worse at night and in the warmth of the bed, and the rash favours specific sites: the webs between the fingers, the wrists, elbows, armpits, the waistline and lower abdomen, the buttocks, the genitals in men, and the area around the nipples in women. In infants, unlike adults, the palms, soles, face and scalp can be involved.

Please understand clearly that scabies has nothing to do with being unclean. It is not a result of poor hygiene, a dirty home or bad habits. It spreads through prolonged, close skin-to-skin contact, which is why it moves through families, hostels, boarding schools, workplaces and old-age homes, and it affects people of every income and background. The mite passes between people who share a bed, between a parent and a child who is carried and held, and between sexual partners. Because the first infestation takes about three to six weeks to start itching, the mite is usually passed on to others in the house long before anyone realises what is happening. This delay, plus the shame attached to the word khujli, is why people try one cream after another from the chemist for months before finally coming to a doctor, by which time several family members are affected.

Diagnosis & Treatment

Diagnosis is usually made clinically, from the pattern and sites of the rash, the night-time itching, and the crucial clue that other people in the house are itching too. A dermatologist examines the finger webs, wrists, waist, genitals and other typical sites, and may use dermoscopy, a simple magnified examination of the skin, to look for the mite or its burrow. In some cases a skin scraping is examined under the microscope. Because scabies is often mistaken for eczema, allergy or a fungal infection, and because steroid creams from a chemist can mask it for a while and change how it looks, it helps enormously to bring along whatever has already been applied.

Treatment uses scabicidal medicines, which are available as creams or lotions applied to the whole body, and as tablets. A topical scabicide is generally applied over the entire body from the neck downwards, including between the fingers and toes, under the nails, the navel, the genitals, the buttock creases and the soles, then left on for the number of hours the doctor advises, usually overnight, before washing off. In infants and the elderly the scalp and face are included as well. A second application after about a week is very commonly advised, because no treatment reliably kills all the eggs in one go. Oral treatment as a single dose repeated after a week is an alternative or an addition in some situations, such as widespread disease, crusted scabies, or an outbreak in a hostel or institution, while safer options are chosen for infants and for women who are pregnant or breastfeeding. Any secondary bacterial infection is treated first or alongside. Which option suits you depends on age, pregnancy, other health conditions and how many people are involved, and that decision should be made by a doctor rather than at the chemist counter.

Two points decide whether treatment succeeds. First, every person living in the house must be treated on the same day, including those with no itching at all, because they may be in the silent few weeks before symptoms appear. Treating only the person who itches is the single most common reason scabies keeps returning to a family. Second, clothes, bedsheets, pillow covers and towels used in the previous few days should be washed in hot water and dried in strong sunlight or ironed, and items that cannot be washed can be sealed in a plastic bag for about a week, since the mite cannot survive long away from human skin. Now the part that worries people most: itching often continues for two to four weeks, and sometimes up to six, after successful treatment. This is the skin settling down from the allergic reaction, not treatment failure, and it is managed with antihistamines, plain moisturiser and a mild prescribed anti-inflammatory cream. Please do not repeat the scabicide again and again for this itch, because overuse irritates the skin and produces a rash of its own that is easily mistaken for persistent scabies. If fresh burrows or new bumps appear after four weeks, or if a household member starts itching later, come back for review rather than restarting treatment on your own.