In recent years, there have been cases in which people have experienced health problems when visiting bathing areas – a skin allergic reaction occurring after swimming in water reservoirs where the microbiological quality of water is good and there are no signs of contamination in visual assessment. There are also no signs of proliferation of blue algae.

If the water flow is slow or the water is stagnant in a swimming pool (careers, lakes), and if the presence of waterbirds and/or water mammals is observed, it should be borne in mind that the presence of microscopic parasites in the water body is possible, which may cause health problems in people with more sensitive skin (skin allergies) - “swimmers itch”.


An allergic skin reaction after a swim, known as “swimmers' itching” or cergic dermatitis, is relatively common throughout the world during the summer months, including climate change is also spreading to our geographical area.

“Swimmers itch” is caused by a reaction to certain microscopic larvae of parasitic worms that infect birds and/or water mammals and then snails in their development. The larval stage released from snails may result in these allergenic effects in sensitive human beings. 

The larvae cannot enter the human body and they die in a short time. In most cases, if “swimmers' itching” has been detected, symptoms may be alleviated by any anti - allergy preparation or skin-calming lotion, but if symptoms do not decrease, advice from a medical practitioner is required. 


In order to avoid undesirable effects of bathing in areas where parasitic maggots may be exposed, the Inspectorate recommends that the following hygiene and precautionary conditions be observed:

  • In children and the rest of the population who are sensitive to various factors causing allergies, do not use a bathing site if there is known information on observed cases of “itching of swimmers” and the surrounding area of the bathing site indicate that there is potential for water contamination with microscopic parasites (if the surroundings are marshy, a large number of snails and waterbirds are present in the water, beavers, water rats or other water mammals)
  • Wipe with the towel immediately after the swim or wash in the shower if it is possible, as larvae do not try to drill into the skin in the water, but try to do so at a time when the swimmer has left the water and the skin gradually dries
  • Do not feed waterbirds in bathing areas and water bodies used for swimming, as this contributes to attracting birds to a specific site.