Cutaneous allergic vasculitis due to Solenopsis geminata (Hymenoptera: Formicidae) envenomation in Indonesia.

Severe cutaneous allergic vasculitis in a 60 year-old Caucasian male following the bite of the tropical fire ant, Solenopsis geminata (F.) is reported. Over the course of 8 weeks, the pathology progressed from an extensive red papular urticaria to vasculitis with peri-vascular inflammation and ulceration of the skin on the feet, ankles and lower limbs. Many of the affected areas of the skin eventually became covered with black eschar associated with further tissue breakdown and ulcer formation. After debridement, compression dressings, antimicrobial ointment and corticosteroids, complete healing eventually took place with only residual scarring. An awareness of the severe dermatologic reactions caused by a bite of S. geminata, albeit rare, is clinically important. Recognizing the characteristic skin lesions caused by the bite of S. geminata, treated with prompt administration of appropriate chemotherapy will speed recuperation of the patient and reduce possible secondary complications.

Pharaoh Ant (Monomorium pharaonis): Newly Identified Important Inhalant Allergens in Bronchial Asthma

The nonstinging house ant, Monomorium pharaonis (pharaoh ant), was recently identified as a cause of respiratory allergy. This study was performed to evaluate the extent of sensitization to pharaoh ant, and its clinical significance in asthmatic patients. We carried out skin prick tests in 318 patients with asthma. Specific IgE (sIgE) to pharaoh ant was measured by ELISA, and cross-reactivity was evaluated by ELISA inhibition tests. Bronchial provocation testing was performed using pharaoh ant extracts. Fifty-eight (18.2%) of 318 patients showed positive skin responses to pharaoh ant, and 25 (7.9%) had an isolated response to pharaoh ant. Positive skin responses to pharaoh ant were significantly higher among patients with non-atopic asthma than among those with atopic asthma (26.0% vs. 14.9%, p<0.05). There was significant correlation between sIgE level and skin responses to pharaoh ant (rho=0.552, p<0.001). The ELISA inhibition tests indicated that pharaoh ant allergens had various pattern of cross-reactivity to house dust mites and cockroaches. Bronchial provocation tests to pharaoh ant were conducted for 9 patients, and eight showed typical asthmatic reactions. In conclusion, pharaoh ant is an important source of aeroallergens, and it should be included in the skin test battery for screening the causative allergens in patients with asthma.