How to identify and treat common bites and stings
A thorough history and physical are key to proper diagnosis and treatment following a patient’s encounter with an insect, arachnid, or other arthropod.
PRACTICE RECOMMENDATIONS
❯ Recommend that patients use an insect repellent, such as an over-the-counter formulation that contains DEET, picaridin, or PMD (a chemical constituent of Eucalyptus citriodora oil) to prevent flea bites. C
❯ Prescribe nonsedating oral antihistamines as first-line symptomatic treatment of mild-to-moderate pruritus secondary to an insect bite. C
❯ When indicated, refer patients for venom immunotherapy, which is approximately 95% effective in preventing or reducing severe systemic reactions and reduces the risk of anaphylaxis and death. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
In contrast, the body of a black widow spider is black; females exhibit a distinctive red or yellow hourglass marking on their ventral aspect.28,31 The pinprick sensation of a bite leads to symptoms that can include erythema, swelling, pain, stiffness, chills, fever, nausea, and stomach pain.30,32
Management. Again, see “Providing relief and advanced care” on page E6. Consider providing antivenin treatment for moderate or severe bites of brown recluse and black widow spiders.
Fleas
Fleas are members of the order Siphonaptera. They are small (1.5-3.2 mm long), reddish brown, wingless, blood-sucking insects with long legs that allow them to jump far (12 or 13 inches) and high (6 or 7 inches).33 Domesticated cats and dogs are the source of most flea infestations, resulting in an increased risk of exposure for humans.34,35 Flea bites, which generally occur on lower extremities, develop into a small, erythematous papule with a halo (FIGURE 4) and associated mild edema, and cause intense pruritus 30 minutes after the bite.35-37
Fleas are a vector for severe microbial infections, including bartonellosis, bubonic plague, cat-flea typhus, murine typhus, cat-scratch disease, rickettsial disease, and tularemia. Tungiasis is an inflammatory burrowing flea infestation—not a secondary infection for which the flea is a vector.34,35
Preventive management. Repellents, including products that contain DEET (N,N-diethyl-meta-toluamide), picaridin (2-[2-hydroxyethyl]-1-piperidinecarboxylic acid 1-methylpropyl ester), and PMD (p-menthane-3,8-diol, a chemical constituent of Eucalyptus citriodora oil) can be used to prevent flea bites in humans.33,38 Studies show that the scent of other botanic oils, including lavender, cedarwood, and peppermint, can also help prevent infestation by fleas; however, these compounds are not as effective as traditional insect repellents.33,38
Flea control is difficult, requiring a multimodal approach to treating the infested animal and its environment.39 Treatment of the infested domestic animal is the primary method of preventing human bites. Nonpesticidal control involves frequent cleaning of carpeting, furniture, animal bedding, and kennels. Insecticides can be applied throughout the house to combat severe infestation.33,38
Continue to: The Centers for Disease Control and Prevention...
