Paddy field dermatitis in Assam: a cercarial dermatitis

Area of Science:

• Occupational Health
• Dermatology
• Parasitology

Background:

• Rice field dermatitis is a prevalent occupational health issue affecting paddy field workers in Assam.
• Affected individuals develop skin exanthema, primarily on exposed limbs, after contact with rice field water.

Purpose of the Study:

• To investigate the causative agent of rice field dermatitis in Assam.
• To identify the source of cercarial infection in paddy fields.

Main Methods:

• Collection and examination of gastropod snails from rice fields for cercarial infection.
• Identification of snail families and schistosome cercariae.
• Experimental exposure of human volunteers to cercariae to confirm pathogenicity.

Main Results:

• Planorbid snails were found to be infected with animal schistosome cercariae.
• These cercariae were confirmed to invade human skin.
• Repeated exposure led to dermatitis in human volunteers, consistent with cercarial dermatitis.

Conclusions:

• Animal schistosome cercariae from planorbid snails in rice fields are the cause of rice field dermatitis.
• This parasitic dermatitis poses a significant occupational health risk to agricultural workers.