Triatomine bug dermatitis is a dermatitis caused by bite from Triatomine bugs, also known as kissing bugs, conenose bugs, and vampire bugs.


Causes

Triatomine bugs can be eggs, nymphs, and adults in the different life stages, with a piercing and sucking mouthpart. Both nymphs and adults can crawl and suck blood. Adults can fly. They are active in summer, hide in the holes or cracks of the walls, door frames, and screens during daytime, and suck human blood at night while humans are asleep.

Triatomine bugs piercing human skin with sharp mouthparts can not only transmit diseases, but also secrete saliva while sucking blood. Saliva contains various active media such as proteins, enzymes, histamine, serotonin, and kallidin, which cause local and systemic allergic reactions.

Figure 1 triatomine bug


Signs and Symptoms

Triatomine bugs suck blood mostly on the face, specially the eyelids, cheeks, corners of the mouth, and lips, as well as on the lower limbs, upper limbs, and back. Each blood sucking takes several minutes to half an hour. Generally, there is no pain during blood sucking. However, it has also been reported that some patients feel skin pain during blood sucking. Soon after blood sucking, pea sized papules or erythema occur, and there is a pinhead sized spot or petechia on the center. Subsequently there are local skin swelling, some patients present with irritation, pain, or burning sensation, and large wheals or angioedema, fever, chest tightness, dizziness, nausea, abdominal pain, and difficulty breathing may occur. Few patients may present anaphylactic shock. There may be only mild erythema in some patients. Skin lesions gradually subside in 4 - 5 days.


Diagnosis

If there are clinical findings, specifically the spot on the center of the skin lesions, and triatomine bugs found by the patients, the disease can be diagnosed.


Treatment

Topical ammonia water, 1:5000 potassium permanganate solution, 1% phenol, peppermint essential oil, and calamine lotion can be applied. If there are systemic symptoms, antihistamines or glucocorticoids may be appropriate.


Prevention

Triatomine bugs can be eliminated by pyrethroid insecticides such as cypermethrin, lambda-cyhalothrin, deltamethrin, or cyfluthrin.