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Bathing Water Quality and Human Health


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Swimmer's dermatitis or "duck itch"

published on 01/08/2008

For some ten year's now, the number of epidemic breakouts in swimmer's dermatitis has both surged and spread, across all European countries, and during the past decade (1990-2000), with one or two breakouts identified in France.


lake with ducks
Swimmer’s dermatitis occurs when “swimming” larvae enter bathers’ skin; they are referred to as “cercarial” and come from certain parasites. The larvae infect certain fowl and molluscs. Spring and summer weather conditions seem to foster the extension of parasitic occurrences.

Health Impacts

Swimmer’s dermatitis is a passing skin affliction that can lead to allergy. The affliction is generally benign, even though the reaction is often very strong.
The dermatitis appears immediately after bathing as a tingling sensation at the larvae penetration points. Soon after, small red patches and vesicles appear and persist five to fifteen days, without leaving any marks, but can lead to severe itching. The breakouts are found on part of the body that remain uncovered by bathing wear.
When exposure is repeated, the lesions can be heightened by a hypersensitive reaction (allergic phenomenon).

Health Recommendations

To relieve swimmer’s dermatitis, no individual protection measures intended to prevent larval skin penetration have officially been validated. The use of a repellent used in certain anti-mosquito products is reported to be effective against the larvae. To reduce risk, taking a shower after bathing, and briskly drying the body with a towel after a bath are also reputed to reduce risk, as it would appear that the larvae remain at the skin’s surface for some time before entering.
Should swimmer’s dermatitis symptoms appear, seek a doctor’s advice or go to a pharmacy to ask for appropriate symptom treatment: local anti-inflammatory creams (dermocorticoids) or, in the event of additional infection, fusidic acid. Applying ice to the affected areas, as soon as the first signs appear, can relieve pain immediately.