Scabies is a contagious skin disease due to Sarcoptes scabiei, an arachnid of the mite group that results in severe itching and on the skin superficial burrows that in some cases have bacterial over-infection.
The females of the mite dig these tunnels in the skin for the purpose of depositing eggs, following fertilization of the male specimen. These have an oval body shape, white/yellow color, four pairs of limbs and measure about 0.3/0.4 mm.
The female dies after deposition in 4-5 weeks while the "mate" is smaller in size and tends to die after mating. Some of the eggs, in fairly small numbers, develop after about 20 days and new adults give birth to other lesions.
Sarcoptes scabiei is cosmopolitan but promiscuity and hygiene/sanitary level are risk elements particularly in endemic areas.
In our travels to non-European countries, one must consider where one is staying, checking for example the change of towels, sheets but also and especially direct contact with potentially infected individuals.
The routes of transmission are ultimately skin, clothing and bedding.
However, it should be considered that skin disease can affect people of any social and cultural level even with a sufficient level of hygiene. So our attention does not always help, but certainly in general tends to limit the risk of contagion perhaps with a trivial observation to those near us who tend to scratch continuously. The incubation period is normally less than 30 days, in most cases three weeks after infection.
As already specified the itching is intense, with exacerbation at night, affecting particularly the lateral surfaces of the fingers, wrists, armpits, glans, penile skin, submammary folds and under the buttocks. Tunnels with vesicles and intense and continuous scratching lesions are observed, and if there are alterations or immunity deficits multiple squamo-cystous lesions.
The tunnel carved into the skin by the mite results in a lesion called the acaric furrow, a relief between 5 and 10 to 15 mm of skin color or only slightly darker. The end of the burrow is raised and called acaric protrusion, and a flat vesicle may form, which is called a pearly vesicle.
The main symptom i.e. itching leads to scratching continuously and so vigorously that it causes bleeding and subsequent scab formation. Secondary erosions and scaling are formed with possible bacterial over-infection (streptococci and staphylococci) that can give rise to other skin lesions. Such itching is especially intense during the night so much so that it awakens and blocks sleep. In fact, during these hours the warmth of the bed, the increase in temperature, create favorable conditions for the activity of the parasite.
In people of color or, in any case, those with dark skin, it is easy to find elevations and solid raised plaques can then be detected.
When this infestation is severe with the presence of scabs it is called Norwegian scabies and as we have already pointed out patients may have alterations and lowering of the immune system or psychophysical disability (in the first case from HIV).
Norwegian scabies presents area of thickened and crusted skin, particularly in palm/plantar area, not itchy but also backs of hands and knees (described in 1848 in Norway).
Remember when you have complaints similar to those listed above, before starting any treatment, you should always consult a dermatologist or a specialist in tropical and infectious diseases, who will accurately diagnose the condition.
Given the above, in general, scabies therapeutically involves the use of scabicides. Local/topical treatment is based on creams or lotions of benzyl benzoate, permethrin or crotamiton particularly used for itching as the active ingredient. Also in galenic preparation.
They should be applied with a strong friction called scrub particularly where the parasite tunnels are detected but also to follow on the whole body, after 12 hours they should be removed with water.
Often emollients and antihistamines are also used for oral administration in order to soothe itching or antibiotics for over-infection of the scratching lesions, bacterial type.
Once therapy has begun, it is necessary to wash clothing, bedding and linens, and bathing linens with warm water, and also subject family or community members or sexual partners to treatment even if they have no symptoms.
Frequent travel and hotel stays are factors that promote the spread of this parasitosis. Then when one has chosen an exotic, tropical vacation it may happen to have to deal with this disease, for example Caribbean and South America. We have had in the more industrialized countries a recent increase in case histories on the pace of immigration waves from developing countries, from the increased promiscuity and increased internationality of our vacations reaching exotic destinations.
On the way back after 2 to 3 weeks an intense itching, particularly at night or the presence on the skin of reddened "paths" similar to small tunnels are important signs that still and always need dermatological control.