An extensive case of dermonecrotic arachnidism

Abstract

Dermonecrotic arachnidism is the potential cutaneous reaction to spider bite venom. The yellow sac spider, genus Cheiracanthium, is historically considered capable of inducing dermonecrotic lesions. However, recently this belief has been hotly debated. In this article, the authors provide a brief review of dermonecrotic arachnidism and describe a case of a 20-year-old man who developed severe necrosis and edema of the left thigh, buttock, penis, and scrotum following the bite of a yellow sac spider. Notably, the patient wore a tight-fitting garment for multiple hours following the spider bite, thus compressing the envenomated tissue. This is the first case reporting such severe dermonecrosis resulting from a yellow sac spider bite and highlights the potential effects of tissue compression following spider envenomation.

Figure 1A

Severely edematous penis and scrotum and purpuric discoloration of the scrotum.

Figure 1B

Edematous left anterior thigh with purpuric discoloration and desquamation. Notice sharp cut off correlating with the elastic banding at the bottom of undergarment girdle.

Figure 2

MRI shows extensive subcutaneous edema with no extension into the intermuscular fascial planes or musculature and no visualized soft tissue gas.