All you need to know about: scabies

Take a look at this number: at least 200 million people worldwide suffer from scabies at any one time. In 2017, the World Health Organization classified scabies as a neglected tropical disease due to its significant burden on impoverished and vulnerable populations. Here is all you need to know about it.

What is scabies?

Scabies is caused by a tiny bug, the Sarcoptes scabiei mite that burrows under the skin, causing an itchy rash. It is a contagious parasitic skin infestation that occurs in all parts of the world and can occur in anyone, but is more common in hot, tropical countries like India. According to the World Health Organization, scabies is one of the commonest dermatological conditions, accounting for a substantial proportion of skin disease in developing countries. 

The condition develops when the female mites (invisible to the naked eye) tunnel their way under the skin, where they live, lay eggs and excrete waste, spreading to other parts of the skin as well. The itchy rash is your body’s allergic reaction this. Scabies spreads easily in crowded conditions and generally through close, direct contact with an infected person, and sometimes through shared clothing and bedding. It can affect anyone, and has nothing to do with a person’s personal cleanliness or hygiene.

What are the signs and symptoms?

The most common symptom is an intense itchy rash that may become worse at night. In those who have not had scabies previously, the rash can take up to six weeks to develop, but in those who’ve had it before, it usually appears within a few days. The mites generally live in the folds of the skin, and can be commonly found: between the fingers and toes, in the armpits, in the folds of the thigs and in the genital area, in the soles of the feet, in the bends at the wrists and knees and elbows, underneath fingernails, around the nipples and belly button, around the waist and on the buttocks.

In infants and young children, the rash can appear on the palms, soles and scalp, and the rash may be larger. Other symptoms of scabies include ‘burrow marks’: these are wavy tracks that appear as lines along the skin and bumps and sores.

What is crusted scabies?

Crusted scabies is a more severe form of the condition that may affect people with weak or suppressed immune systems. While most people with typical scabies are infected with 10 to 15 mites, people with crusted scabies may be infected with thousands or even millions of mites. This form of scabies can cause large sections of the skin to become crusted and scaly It is very contagious and hard to treat and can cause secondary infections if not treated on time. Prompt diagnosis and treatment are essential.

Treatment and prevention

Treatment of scabies is usually with topical creams and oral medication. The itchiness, however, can persist for a few weeks after treatment. Creams, lotions or ointments may be prescribed. Often these need to be applied on the whole body from the neck downward and be left on the body for 8 to 14 hours. Children may require to have the cream spread on their faces or scalps. Repeated treatments may be required if symptoms reappear.

Ivermectin is an oral medication for scabies treatment; however, it cannot be taken by pregnant and children weighing less than 15 kg. Other oral medications that may be prescribed include antihistamines and antibiotics, if there is an infection.

As scabies is contagious, prevention can go a long way towards ensuring there are no outbreaks. It is recommended that all persons in an affected person’s household be treated even if they have no symptoms. In addition it is recommended to avoid close contact with patients. All bedding should be thoroughly washed in hot water and dried in direct sunlight or in a dryer, as heat can kill the mites and eggs. Any items that cannot be washed should be placed in a sealed plastic bag for at least a week. All rooms in the house should be thoroughly cleaned and vacuumed after treatment.