Diagnosis
The physician tries to gain information about the type of underlying disease in itchy anus primarily through a thorough anamnesis and physical examination, which naturally includes a careful examination of the anal region and rectum. When examining the rectum, in addition to the digital rectal examination with the finger, it may also be necessary to inspect the rectum with the aid of a speculum. If the doctor finds visible suspicious skin lesions, a biopsy can be taken to clarify any cancer that may be present.
If no diagnosis is made even after thorough examination of the anal region and rectum, additional measures such as endoscopy of the entire colon (colonoscopy) may be necessary. Blood tests can provide information about any metabolic diseases or diseases of the immune system. The first point of contact for itching should be the family doctor. He can approach the problem by taking a thorough anamnesis and examination and, if necessary, refer you to a specialist. Skin diseases are the responsibility of the dermatologist or allergologist, diseases of the gastrointestinal tract the responsibility of the gastroenterologist and for diseases of the rectum and the anal region the proctologist is responsible.
After itching in children
Anal itching (pruritus ani) is generally less common in children. The triggers are essentially the same as in adults, except for the hemorrhoidal disorder, which does not occur in children. The problem should also be taken seriously in children.
A medical clarification can show whether a serious illness such as diabetes or a chronic inflammatory disease is the cause or whether an adjustment of the hygiene measures is sufficient to alleviate the symptoms. By far the most common cause of anal itching in children is enterobiasis, an infection with the pinworm Enterobius vermicularis, which can cause severe itching at night (see below). This can be treated with special medication against worms.
Nocturnal itching
The most common cause of anal itching at night is an infection with the so-called pinworm, lat. Enterobius vermicularis. The pinworm is a parasitic nematode living in the human intestine and is one of the most common parasites in humans.
About half of all people fall ill at least once in their lives. Infection occurs through ingestion of dust contaminated with worm eggs through the mouth or faecal-oral. The ingested worm eggs enter the duodenum via the stomach, causing the egg shell to soften.
After about six hours the first larvae develop, which migrate through the intestine and settle on the intestinal wall near the appendix. There, together with their host, humans, they form a so-called commensal (feeding community) by feeding on the food remains in the large intestine. The immediate vicinity of the colon is also the place of mating.
About two weeks after fertilisation, the females migrate towards the anus to lay their eggs. During this, mostly nocturnal process, a strong itching in the anal region develops, which can lead to sleep disturbances, irritability, lack of concentration and severe scratching in the anal region. Eggs that collect under the fingernails when scratching can lead to reinfection by reabsorption through the mouth.
Enterobiasis, i.e. infection with the pinworm, is harmless in the majority of cases, although it is very annoying due to the sometimes severe itching. If a disease is suspected, it can be diagnosed by a simple procedure. In the morning an adhesive strip is applied to the anal region, immediately removed and examined under a microscope for the presence of worm eggs. The treatment is carried out with anti-worm agents such as Mebendazole, which is administered orally and is also well tolerated by children.