Schistosomiasis (Bilharziosis) and the Skin (For professionals)

Synomyms: bilharzia, bilharziosis, snail fever.

• It is due to an infection by a trematode (flatworm or fluke) of the Schistosomia family.
• It is a disease frequent in Africa, Asia and South America where lakes containing freshwater snails are present. Children playing in the water are the first victims.
• Symptoms and signs of this infection are that of a chronic disease and include anaemia, malnutrition, abdominal pain, diarrhea, eosinophilia, fatigue…There is a long term increased risk of bladder cancer.
• Treatment with an anthelminthic is readily available.
• The fluke has a complex life cycle involving an intermediate host (freshwater snails) and then humans (free swimming cerceriae (larvae) that penetrate the skin). Skin manifestations are included here.

1. Skin penetration induces burning and pruritus followed by echhymoses, bullae and crusted papules over several days.
2. The worm maturates in the portal or caval veins and releases ova which go into the urine or faeces. The ova on contact of the skin may induce nodules, ulcers, and verrucous  lesions. If the ova enter the lymphatic system, the lesions may occur thoughout the body.

Bibliography

Dermatology Secrets 3rd Edition

Wikipedia