Many species of arthropods (insects, arachnids, millipedes and centipedes) can bite or sting human beings.

While most cases cause self-limited irritation, medically relevant complications include envenomation, allergic reactions, and transmission of vector-borne diseases.

[2][3] Many arthropods bite or sting in order to immobilize their prey or deter potential predators as a defense mechanism.

The low mortality (around 60 deaths per year in the US out of unreported millions of stings nationwide) associated with Hymenoptera is mostly due to anaphylaxis from venom hypersensitivity.

Severe toxic reactions can occur resulting in progressive hemodynamic instability, neuromuscular dysfunction, cardiogenic shock, pulmonary edema, multi-organ failure, and death.

Although robust epidemiological data is unavailable, global estimates of scorpion stings exceed 1.2 million resulting in more than 3000 deaths annually.

Symptoms of latrodectism (from widow spiders) may include pain at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others.

By comparison, loxoscelism (from recluse spiders) can present with local necrosis of the surrounding skin and widespread breakdown of red blood cells.

[8] The World Health Organization (WHO) estimates that 17% of all infectious diseases worldwide were transmitted by arthropod vectors, resulting in over 700,000 deaths annually.

Protozoa (Plasmodia) Nematode (Wuchereria bancrofti) Malaria Lymphatic filariasis (Simuliidae) (Reduviidae) (Phlebotominae) (Ixodidae)

Babesiosis (Glossinidae) (Tabanidae) (Siphonaptera, Pulicidae) (Phthiraptera, Pediculidae) *Estimated global number of cases annually according to WHO in 2017.

[11] Rather, patient history (recent travel to endemic areas, outdoor activities, and other risk factors) primarily guides the diagnostic approach, which can raise clinical suspicion for more serious complications like vector-borne diseases.

Bites and stings as well as other conditions (e.g. drug reactions, urticarial reactions, and early bullous pemphigoid) can cause microscopic changes such as a wedge-shaped superficial dermal perivascular infiltrate consisting of abundant lymphocytes and scattered eosinophils, as shown in the adjacent figure:[12] Prevention strategies against arthropod bites and stings comprise measures for personal protection, travel advisories, public health and environmental concerns.

Clothes covering most exposed skin can also provide a measure of physical protection, which may be augmented when the fabric is treated with pesticides such as Permethrin.

[14] Such campaigns must incorporate multipronged approaches to consider global inequality, access to resources, and climate change.

Oral antihistamines, calamine lotion, topical corticosteroids and cold compresses are common over the counter remedies to reduce itchiness and local inflammation.

In more severe cases, such as large local reactions, systemic glucocorticoids are sometimes prescribed, although limited evidence supports their effectiveness.