CAMAGÜEY.- Pediculosis are parasitic dermatosis caused by the presence of parasites in the skin and adnexal structures, the latter include, among other parts, the hairs, and they feed on our body and use it for its life cycle, as those tiny insects feed on human blood.

This condition lies in skin infestations by a group of insects called pedicles or lice and humans can be affected by three of them: the pediculus humanus capitis (human head louse), the pediculus humanus corporis (body louse or of clothing), and the pthirus pubis (crabs or pubic louse).

The explanation was given by Dr. Yunet Pimentel Fraga, specialist in Comprehensive General Medicine (MGI) and in Dermatology, of the Joaquín de Agüero polyclinic (North) of this city.

- Can you characterize these insects for me?

—Lice are insects without wings, which belong to the order of anoplura insects; those of the head and body are morphologically identical, measure between two and four millimeters and the body is elongated; those of the pubis are smaller, between one or two millimeters, with the widest and round body. All have three pairs of legs ending in hooks or tweezers that they use to attach to the hair. Since lice are blood-feeding and inject saliva to feed, they resist a few days when they are not in contact with the host. There are those that affect animals, but those have nothing to do with those mentioned, they do not infect humans and vice versa.

“Both eggs and nymphs and adults are very sensitive to sudden changes in temperature and die above 40 degrees Celsius. Those of the head inhabit more frequently in the occipital area (back), and behind the ears. The degree of infestation is low, from 20 to 30 adult lice per person and they move up to 23 centimeters per minute, with a very short life that approaches the month and the female lays between seven and ten eggs per day, which are laid one for each hair, near the root and take advantage of body heat.

“The body louse has a life cycle similar to that of the head, but the eggs are deposited in the clothes, especially inside the seams, only some adhere to the hairs of the body, but most go, bite and they return to clothes. Those of the pubis with a very similar life cycle; however, they are deposited at very short distances between the skin and the hair and after the first contact they remain attached to the pubic hair with preference of the oral apparatus introduced into the host, it is always feeding, the contagion is sexual and rarely invades the armpits, the beard, the periphery of the scalp and also in the eyelashes, but with the fashion of shaving is less frequent, although this practice brings other problems that can be addressed in another consultation of this type.

- Why don't they fall alone and have to be removed?"

— Each egg or nits is fixed by a cementing substance (similar to the cement that females make when they lay eggs). Inside this capsule is where the future louse is incubating until it is ready and hatches, a process that occurs between seven and ten days, which embraces in the form of a sheath by the lower pole. The egg will remain attached to the hair, even, once hatched and empty, hence the terms of live and dry nits; the incubation period is seven days and after hatching the nymphs require seven more days to reach adulthood and sexual maturity.

- If they don't have wings, how do they pass from person to person?"

—The infestation is transmitted by hats, caps, useful for combing, when exchanging sunglasses and, of course, by direct contact between people, and hence the frequent epidemics in schools or wherever there is overcrowding of individuals . The lice walk, and something that is very fashionable, take selfie with someone, since they put their heads together, they can move from an affected person to a healthy one.

—What are the symptoms?

—Many itching, and due to that intense itching caused by the stinging and injection of saliva to feed, it is what causes a hypersensitivity reaction, and something to keep in mind is that when you put continuity solutions on the head secondary infections occur and may suffer from what we know as a stinky braid or "polonic plica", degree of suffering that is when people do not care and their hygienic habits are bad.- Those affected go to the doctor frequently?

—As they are identified and it is not a worrying disease, they do not go, and even sometimes hide it even out of grief or shame.

- Do they have a predilection for some age and sex?"

—Very frequent in childhood, between the ages of five and 12, and no predilection of sex.

Dr. Yunet suggested mentioning myths and realities about the subject, and here I relate them:

- Can other myths be expressions such as: "no blood for lice" or "only dirty people suffer"?

—Indeed, they have no relationship. Just as the body's defenses are different from any disease, the same thing happens in this case, it is not the blood, it depends on the susceptibility of the individual and with hygiene the same thing happens, those who are very clean are also infected, which is more difficult control or cure them in those who do not maintain proper hygiene habits, that is something else.

"For this misconception that those who face this condition are not clean people stop attending the doctor, and that attitude causes other ailments such as: contact dermatitis, poisoning, conjunctivitis or allergic and inflammatory reactions, due to the application of homemade solutions without a scientific basis ”.

- In this type of consultation we do not address issues related to medications, but given the situation of cases like this, which avoid visiting the doctor, what do you advise?

—It is ideal to assist the doctor, but since that cement substance of the nit dissolves with the vinegar or acetic acid, it is good to apply it for half an hour and even until the next day, because it is alive or dry and then extracted with the combs called nits, because as we know the louse is removed manually. Drug shampoos usually help, but they began to gain resistance to some of those products.

- If this type of involvement is known in a children's circle or school, what would be the most appropriate measure?

—The affected person must be suspended until the episode is verified, and that responsibility belongs to the parents and teachers. There is no need to be upset about it, so the healthy ones are protected and the re-infestation of the same one. Avoiding is the best.

Translated by Linet Acuña Quilez