Two weeks ago, the T&T Guardian in association with the Trinidad and Tobago Dermatological Society began a series on common local skin problems. The series continues today and will run on Saturday for the next eight weeks.
Human scabies, a highly contagious, itchy skin infestation, is caused by a mite called sarcoptes scabei var hominis. This condition is commonly seen in families, children usually being the first affected. It needs warmth and close prolonged contact for its spread and can live in bed linen or furniture for up to three days. The entire life cycle of the mite lasts 30 days. The female mite burrows into the upper layers of the skin and lays about 60-90 eggs. It takes about ten days for eggs to become adult mites-only ten per cent may reach that stage. Scabies is a worldwide public health concern affecting any age group, race and socio-economic group. There is a similar mite on dogs but animal scabies mites are not a cause of persistent infestation in human beings. The appearance on dogs may look like mange. It must be emphasized that human scabies is spread from person to person especially where there is close contact over prolonged periods. It is not usually a condition that is caught from dogs.
Signs and symptoms
The diagnosis of scabies can be delayed because it may manifest itself in many ways. The signs and symptoms take a few days, sometimes weeks, after acquiring the mite, to appear. There is typically intense itching which is worse at night and will also be found in other family members. In adults, the red lesions which may look like small water blisters or bumps are found in webs of fingers, wrists, under arms, elbows, waist, buttocks and genitals. A common characteristic feature is the itchy lesions on the breasts, around the navel and, in men, the penis and scrotum. Infants and children have as well, involvement of the face, neck, scalp, palms of the hands and soles of the feet. Babies may also get larger hard bumps called nodules.
Burrows where the female mites live may appear as dirty-looking curved lines less than one inch long, on webs of fingers, wrists, elbows, scrotum and soles. The mite or its broken parts can be seen when the burrows are scraped by the doctor and examined under a microscope however it is not necessary to do this to make a diagnosis. Scratch marks are commonly seen and may easily become infected. Children commonly may present with an eczema-type of eruption which may lead to a failure in diagnosing scabies. Patients whose immune systems are not functioning well because of HIV disease, treatment for different types of cancers, and old age are particularly at risk for the crusted scabies variant. In this type, there can be about a million mites whereas in the common type there may be less than 100-usually about 10-15 mites.
Treatment
It is important to stress that treatment of the entire family and other close contacts is necessary with a scabicidal treatment left on the skin for about 12 hours. Treatment must be applied from neck to toes but if the scalp is involved in babies some must be applied there also. Infants and young children should wear mittens to prevent hands with medication from being inadvertently placed in the mouth. A second application is done five days later if symptoms are still present. Treatment must not be applied repeatedly on a daily basis, especially in children. Your doctor may give oral antibiotics if there is secondary infection, oral antihistamines for itching and a mild topical steroid after the initial scabicidal treatment. All clothing, bed linen, towels used within the previous few days should be washed in hot water. Cushions and stuffed toys must be placed in hot sunlight if they cannot be washed or put in sealed plastic bags for one week. Submitted by the Trinidad and Tobago Dermatological Society.