Reaction types
Non-IgE-mediated
reactions
Several blood-feeding Arachnida affect human health. Hemolytic
and proteolytic enzymes in spider and scorpion venoms may have severe
cytotoxic, neurotoxic or cardiotoxic effects142 and
can cause acute generalized exanthematous pustulosis
(AGEP),143-146 erythema
multiforme147, and Drug Rash with Eosinophilia and
Systemic Symptoms (DRESS).148 Ticks are generally
known as vectors of bacterial infections (e.g. Lyme disease).Amblyomma tick bites may cause local annular erythema of unclear
pathogenesis known as Southern tick-associated rash illness
(STARI).149
Mite and ticks bites can provoke itching and local hypersensitivity
reactions such as papular urticaria and vesiculopapular eruptions
thought to be due to immune reactions to salivary proteins. Also
“summer penile syndrome” in children, is considered to be an
immunologic hypersensitivity reaction to chigger
bites.150