Black ant stings caused by Pachycondyla sennaarensis: a significant health hazard

Abstract

Several species of ants cause stings, but not all lead to allergic reactions. We present a series of cases of allergic reactions following insect bites or stings that presented to our emergency department and that were caused by the black samsum ant (Pachycondyla sennaarensis). Reactions ranged from mild allergic reactions to severe anaphylactic shock. Patients were treated with subcutaneous epinephrine 0.3 mg, intravenous methylprednisolone 125 mg, intravenous diphenhydramine HCl 50 mg, and intravenous normal saline as appropriate. These cases illustrate the range of clinical presentations to black ant stings, which can include severe reactions, indicating that ant stings are a significant public health hazard in Saudi Arabia. Physicians in the Middle East and Asia need to be aware of ant stings as a cause of severe allergic reactions.

Figure 1

Photograph of Pachycondyla sennaarensis (black samsum ant). Used with permission of Mike J. Lush, sifolinia. blogspot.com, 2009.

Figure 2

Electron microscope image of the stinger of Pachycondyla sennaarensis which injects allergenic venom. From the Museum of Entomology in Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia (Courtesy of Dr. M. Khalifa).

Figure 3

Simple algorithm for treating patients presenting with acute anaphylaxis.