It isn’t new to find the Atlantic Portuguese man-of-war along the coastal beaches of the Vineyard. What is new however, is a soon-to-be-published review of the medical literature discussing the different treatment recommendations for a variety of jellyfish stings, ending with a summarized practical approach to the different species.

The Portuguese man of war is easily recognized by its blue or pink-violet iridescent floating sail, which is inflated with gases. Up to 11 inches long, it is found on the surface of the water or washed up on the beach. Beneath this floating sail dangle hundreds of thousands of stinging cells on transparent tentacles up to 98 feet in length, coiled into “stinging batteries.” When the tentacle brushes against an unwary swimmer, microscopic harpoon devices in the stinging cells inject venom containing a variety of chemicals which cause local skin reactions that are mild to severe, and very painful. Life-threatening reactions are fortunately rare.

Understanding the man-of-war construction and method of injury should help guide preventative measures. When possible, wear rash guard or protective clothing to reduce exposed skin surface area in the water, give jellyfish a wide berth to avoid the long, trailing tentacles, avoid handling beached man-of-war or their tentacle fragments which retain stinging potency for weeks. Consider Safe Sea lotion if a swimmer is at high risk.

Management of stings consists of the following steps:

• Rescue the victim from the water as soon as possible to avoid further contact with jellyfish tentacles.

• Prevent the victim from rubbing the stung area, as that may enhance discharge of venom from the stinging cells on the skin.

• If the person develops hives (red, raised skin welts), wheezing, chest tightness, shortness of breath, difficulty talking or breathing, dizziness, light-headedness, or feeling faint, call for urgent medical assistance to treat a possible allergic (anaphylactic) reaction.

Specific treatment measures include the following:

• Wash the tentacles off the affected areas with seawater, not fresh water. Do not try to deactivate the undischarged stinging cells with vinegar — this may actually make them discharge! There is no evidence on the effectiveness of most of the other treatments often suggested, e.g., meat tenderizer, urine, alcohol, other home remedies, etc., specifically for man-of-war stings.

• Remove clinging tentacles quickly with a cloth, a knife, forceps, tweezers, a firm-edged object such as a credit card, or manually while wearing rubber gloves, but never with bare hands.

• For pain control, immerse the affected area in non-scalding hot water (110° to 113°F), using a hot shower, bath, or soaks for 20 minutes. If local pain is unrelieved by heat or if hot water is not available, consider application of a cold pack or ice in a dry plastic bag. (It does sound contradictory, but try it).

• Antihistamines such as Benadryl, and pain relievers such as Tylenol may ease the subsequent discomfort, as well as topical cortisone cream.

Dr. Michael Jacobs
Vineyard Haven