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Introduction
This is a reaction of the immunity which occurs in humans in the skin. It’s water borne disease caused by Schistosomatidae which is a parasite.
Epidemiology:
Swimmer’s itch is a disease that is common in the whole world. Unlike adults children are more infected.
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Causes & Risk factors
During the lifecycle of the water snail which is usually found in the fresh water, the flat worm takes host in it. These flat worms are in the family Schistosomatidae and the most common cause of the infection is the trichobilharzia and Gigantobilharzia which are the causative parasites.
Cercaria, which is the larva of the parasite swims in the water freely during on stage of their lifecycle. Their main aim is to look for water birds. If accidentally the cercaria comes into direct contact with the skin of a swimmer or anyone in the water, it penetrates the skin and dies immediately. The cercaria is harmless to humans but on entry they cause a reaction of the immune which will lead to inflammation causing itchy spots on the skin of the infected person. The spots turn into papules within minutes. They are more intensely itchy than the spots. The penetration of each parasite on a specific place leads to formation of a papule at that point.
The infection is considered to be higher :-
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When swimming in fresh waters that have a slow motion
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During the mornings and on a day that is sunny. This is because studies show that there is more shedding of the cercariae by the snail on such a day because if offers a more convenient conditions
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In shallow waters that are inshore this is because this is the main habitat of the snail.
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Presence of fatty acids that are unsaturated can increase the penetration stimuli of the cercarial into the host skin. These fats are found naturally on the skin or in some lotions and creams.
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Symptoms and signs
The symptoms of Cercarial dermatitis is
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Being itchy. This occurs within two days of the infection
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Papules being raised. They are red in color
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Diagnosis
There is no specific way of finding of the papules are due to Swimmer’s itch or other infections like chicken pox.
The parasite main habitat is the fresh water or the water fowl. This is because this is the main habitats of the snails which are the hosts of the parasites. As the cercaria enters the human body it dies as it is not a conducive environment for it to survive.
Differential Diagnosis:
In case you are from swimming and you get the itches it is advisable to see a doctor or a specialist. | |
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Investigations
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Cercariae film test
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Ring precipitation test eggs
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Indirect hemagglutination test
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Enzyme-linked immunosorbent assay (ELISA)
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Enzyme-linked immunosorbent electrophoresis assay
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Determination of circulating antigen
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Treatment
Due to the fact that the papules that occur in the Swimmer’s itch are similar to the other skin problem, there has never been a specific way to diagnose if the infection is there or not. The most appropriate thing is if you get an infection after swimming or being in an area that can lead to infection you should visit the doctor.
Medical Treatment:
Administration of medicine like hydroxyzine orally is a common prescription for the reaction of the Swimmer’s itch. Hydroxyzine is an antihistamine.
Sometime the remedy for the swimmer’s itch is a remedy which is made at homes. This includes a lotion which is used to make the skin smooth, colloidal oat meals which are used in bathing and the baking soda also used in bathing. These remedies can be used to lessen the symptoms of the swimmer’s itch.
Any other Treatment:
One of the ways in which areas which have been infected by snails is through the use of copper sulphate which is a molluscicide. This is not a reliable method as it: -
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It made the snail intolerant to copper sulphate
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Due to the chemistry of the water which is local there is reduction in its efficiency
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The currents in the area leads to it diffusing
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The population of snails in the adjacent area come and populate the treated area
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The molluscicide is not only harmful to the parasite but to also other aquatic plants and animals.
The method that has been successful at least is the use of the disturbing the habitats of the snails mechanically. This method has been used in the North America and Lake Annecy which is found in the France.
The other is through educating the public on the strategies that can be used to reduce the effect of Swimmer’s itch. | |
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Complications Of Disease
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The Swimmers itch is an infection which has no major complication. On entry of the cercaria, it dies causing a disturbance to immunity hence a reaction occurs which leads to inching. The parasites are the main course of the itch.
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The itch last only for only a short while. It clears up on its own within a few days of infection, though to reduce the itchiness there are some medication and home maid remedies that can be used.
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In case the rash lasts for more than a week it is advisable to see a doctor. The other reason why you should visit the doctor is in case the papules have pus in them. Seeing a specialized doctor of the skin (dermatologist) is a better option.
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Prognosis
The infected area should be identified and treated or otherwise avoided. | |
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Prevention
The best way to prevent the infection by Swimmer’s itch is through :-
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Avoiding fresh water and water fowls mostly on days that are sunny and during the mornings
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Inshore waters are also not appropriate as they are the main habitats of the snails
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As children have a higher risk of infection they should avoid swimming in area that may be infested with snails
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Not applying yourself lotions which have high concentration of unsaturated fatty acids as they encourage the cercariae to penetrate the body.
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References
www.ncbi.nlm.nih.gov
Hoeffler DF. "Swimmers' itch" (cercarial dermatitis). Cutis 1977;19:461-7. | |