How to identify and treat common bites and stings

Management. Advise patients to reduce their risk by using insect repellent, sleeping under mosquito netting, and wearing a long-sleeve shirt and long pants when traveling to endemic areas or when a local outbreak occurs.⁴⁸

Ticks

Ticks belong to the order Parasitiformes and families Ixodidae and Argasidae. Hard ticks are found in brushy fields and tall grasses and can bite and feed on humans for days. Soft ticks are generally found around animal nests.²⁹ Tick bites can cause a local reaction that includes painful, erythematous, inflammatory papular lesions (FIGURE 7).⁴⁹

Ticks can transmit several infectious diseases. Depending on the microbial pathogen and the genus and species of tick, it takes 2 to 96 hours for the tick to attach to skin and transmit the pathogen to the human host. The TABLE^29,49,50 provides an overview of tick species in the United States, diseases that they can transmit, and the geographic distribution of those diseases.

Management. Ticks should be removed with fine-tipped tweezers. Grasp the body of the tick close to the skin and pull upward while applying steady, even pressure. After removing the tick, clean the bite and the surrounding area with alcohol or with soap and water. Dispose of a live tick by flushing it down the toilet; or, kill it in alcohol and either seal it in a bag with tape or place it in a container.⁵⁰

Diagnosis and the utilityof special testing

The diagnosis of insect, arachnid, and other arthropod bites and stings depends on the history, including obtaining a record of possible exposure and a travel history; the timing of the bite or sting; and associated signs and symptoms.^18,51

Venom skin testing. For Hymenoptera stings, intradermal tests using a venom concentration of 0.001 to 1 μg/mL are positive in 65% to 80% of patients with a history of a systemic insect-sting allergic reaction. A negative venom skin test can occur during the 3-to-6-week refractory period after a sting reaction or many years later, which represents a loss of sensitivity. Positive venom skin tests are used to confirm allergy and identify specific insects to which the patient is allergic.^11,12

Continue to: Allergen-specific IgE antibody testing.