Moon Jellyfish Stings

Envenomation by jellyfish is a common occurrence affecting millions of individuals yearly. Little literature exists on jellyfish stings caused by the “moon jellyfish,” Aurelia aurita. The main objective of the present report is to illustrate that A aurita stings are not as benign as once thought and to propose a treatment sequence for jellyfish stings to address the local cutaneous reactions that these stings can cause.

A healthy 25-year-old white man was stung on the right wrist and forearm while scuba diving at night off of Fort Lauderdale, Florida. Images of the jellyfish were captured by an underwater camera and compared with reference images to confirm the species as A aurita, otherwise known as the moon jellyfish. Of note, these particular specimens were quite large compared with ones more frequently seen. Contact with the jellyfish led to intense stinging pain followed by subsequent pruritus and the formation of urticaria after a few minutes that persisted for several hours (Figure, A).

Initial treatment aimed at removal of nematocysts followed by control of pain and pruritus. Within a few minutes of being stung, the area was exfoliated with sand mixed with seawater to remove nematocysts. Subsequently, the forearm and wrist area was soaked in warm acidic white vinegar, 5%, solution for half an hour to remove remaining nematocysts. Use of vinegar has been purported to block the discharge of nematocysts in other species of jellyfish, although reports are conflicting.¹ Ibuprofen, 500 mg twice daily, was taken as an analgesic for the first 2 days.

The second step involved mitigation of the urticarial reaction and reduction of pruritus. Hydrocortisone has been shown to relieve pain and reduce inflammation due to stings from other species of jellyfish but has not been shown to treat Aaurita stings.² A topical hydrocortisone, 1%, cream was applied to the affected area 3 times daily to control pain and inflammation. Six hours after the initial sting, vesiculopapular erythematous areas were noted, with a coalescence of vesicles over the area most affected by day 2 (Figure, B and C). Vesicles persisted until the third day and subsequently ruptured.

The area was then treated with the topical triple antibiotic combination of bacitracin zinc, neomycin sulfate, and polymyxin B sulfate 3 times daily for 3 days, and steroid applications were discontinued. Scabbing was noted shortly after rupture of the vesicles that healed with time (Figure, D and E).

After discontinuation of treatment with the triple antibiotic ointment, a pea-sized amount of aloe vera gel was applied to the affected area to soothe residual irritation. The lesions resolved by day 8 (Figure, F), 2 days sooner than reported in a case where no treatment was given³ and in a study where purified venom was applied directly to the skin.⁴

An in vitro study has shown that Aaurita toxin can be both hemolytic and proteolytic to human cells.⁵ This has led to the assertion that although the vast majority of Aaurita individuals in a particular area are innocuous, some may cause harm to humans. Herein and in an earlier report of a moon jellyfish sting,³ it was noted that the stinging animals were quite large for the species. Larger jellyfish contain larger cnidoblasts, which house the stinging nematocysts, and the larger nematocysts may penetrate the human epidermis sufficiently, unlike those of smaller specimens, to cause a local dermatologic reaction at the site of exposure.

The course of Aaurita stings involves an intense pruritic vesiculopapular erythematous eruption that lasts 10 days without intervention. However, with the use of readily available over-the-counter medications and common household ingredients, the sequelae of Aaurita stings can be managed effectively, allowing the lesions to clear earlier.

Corresponding Author: Brian J. Simmons, BS, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1475 NW 12th Ave, Miami, FL 33136 (bjsimmons@med.miami.edu).

Published Online: December 17, 2014. doi:10.1001/jamadermatol.2014.4644.

Conflict of Interest Disclosures: None reported.