Sandfly bites, causes, symptoms, diagnosis, and treatment

Sandfly bites are lesions caused by bites from sandflies.


Causes

Female sandflies lay their eggs in dark and humid soil, cracks in walls, soil holes, and rat holes. Each female only has a copulation in her lifetime. Females lay eggs 3 - 5 days after copulation. Each female lays about 50 eggs in her lifetime. Females must suck blood before laying eggs, or else the eggs cannot develop.

Male sandflies do not suck blood but ingest the leaf juice of plants. Females suck human blood from dusk to the early morning, and hide in dark, windless areas during daytime. Sandflies often fly short-distance jumps on the walls of their habitats due to their poor flying ability. Males die shortly after copulation, while females can survive for 2 - 3 weeks. The larvae have strong cold tolerance and survive through the winter in the shallow soil. Sandflies can not only bite and suck blood, but are also vectors to transmit black fever, sandfly fever, and oriental sore.


Signs and Symptoms

Sand flies pierce the skin with the beak on their head and suck the blood of humans and animals. After being bitten, some individuals may be asymptomatic, and some may present with mild or severe pruritus and even sharp pain. There may be local lesions such as red papules, wheals, small nodules, vesicles, and erosions, leaving pigmentation after healing. If the sandfly contains Leishmania-donovani bodies, black fever may occur when it bites human skin. After multiple bites, there may be not reactions on the skin, suggesting desensitization.


Diagnosis

If there are sandflies found and clinical presentations, the disease can be diagnosed.


Treatment

Topical calamine lotion can be used, and oral antihistamines are appropriate if there are systemic symptoms.