Chiggers Trombiculidae

Chigger infestations are caused by mite larvae that feed on host skin cells. European varieties of these arachnids are called harvest mites. The combination of the effect of digestive enzymes secreted by the mite and an immune response of the host produces the typical pruritic lesions. Although the usual response is intense pruritus at the bite site, more severe systemic reactions and chigger-borne diseases also may occur. Mites live comfortably in warm and cold climates. There are approximately 2500 species of chigger mites, with Trombicula alfreddugesi the most common. Mites are quite small, 0.3 to 1.0 mm in length, and attach themselves to the host skin with their mandibular structures, known as chelicerae. Once attached they release digestive enzymes to liquefy epidermal cells, leading to an immune response in the victim and subsequent symptomotology.

Itching usually begins a few hours after the chigger bite, with a papule developing initially that ultimately enlarges over 24 to 48 h to form a nodule. Pruritus usually peaks on the second day, and the nodules can persist for up to 14 days. Children who play or sit on the grass are prone to chigger bites in the genital area. Bites can manifest in some patients as impressive soft tissue edema (Fig 1.88-7). Mite infestations may be associated with fever and an erythema multiforme-like rash. The diagnosis of chigger infestation usually can be made on the basis of known outdoor exposure and typical skin lesions.

The treatment of chigger bites consists largely of symptomatic measures to control the itching. Chiggers may be killed with lindane 1% topical lotion or crotamiton 10% topical lotion (Eurax, Westwood-Squibb Pharmaceuticals). For moderate to severe cases, topical steroid creams and oral antihistamines may provide some relief. There have been reports of systemic steroids providing relief for severe pruritus. If secondary infection occurs, antibiotic therapy is indicated. Clothes fitting snugly at the neck, wrists, and ankles, supplemented with insect repellent, can help prevent chigger infestation.

How To Deal With Rosacea and Eczema

How To Deal With Rosacea and Eczema

Rosacea and Eczema are two skin conditions that are fairly commonly found throughout the world. Each of them is characterized by different features, and can be both discomfiting as well as result in undesirable appearance features. In a nutshell, theyre problems that many would want to deal with.

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