Lesson of the Week: Seabather's eruption—a case of Caribbean itch
Seabather's eruption is an intensely pruritic dermatitis that occurs after exposure to seawater and affects the areas of the body covered by swimwear. It has probably existed for centuries, but formal reports of it are relatively recent.1 With the increasing popularity of foreign travel, seabather's eruption is likely to be seen more often in patients returning from tropical climes. Larvae of species belonging to the phylum Cnidaria—which comprises jellyfish, corals, sea anemones, and hydra—have been implicated as the cause of this condition.2 3 4 The members of this phylum share a similar stinging mechanism, which is mediated by subcellular organelles called nematocysts. We report two recent cases of seabather's eruption caused by the larvae of thimble jellyfish (Linuche unguiculata).

Seabather's eruption should be suspected if there is a history of exposure to seawater followed by the appearance of a papular, pruritic rash affecting the areas covered by the swimsuit

In May a 31 year old accountant and her husband travelled to Cancun, on the Caribbean coast of Mexico, for their honeymoon. On the last day of the trip they took a final swim in the ocean, and within minutes of entering the water they became aware of a …
Seabather's eruption. Clinical, histologic, and immunologic features.
BACKGROUND
Seabather's eruption (SE) is a highly pruritic eruption under swimwear that occurs after bathing in the ocean. Its cause has been unknown. Few data have been collected since the classic description by Sams in 1949.


OBJECTIVE
Our purpose was to describe the clinical and histopathologic findings in SE and to confirm the cause.


METHODS
Patients with a pruritic eruption that developed after swimming were seen within 1 week of onset. Skin biopsy specimens and sera were obtained in selected cases. Water samples taken from areas of active SE outbreaks were examined for a causative organism. Sera were tested by enzyme-linked immunosorbent assay for reactivity to this organism.


RESULTS
In southeast Florida, during a 4-month period, 70 patients with SE were seen. Inflammatory papules and pruritus were noted within hours of exposure. Eruptions were maximal in areas covered by a bathing suit. Children were more likely than adults to have systemic symptoms. The average duration of the eruption and pruritus was 12.5 days, with recurrences in 4.3% of patients. Histopathologic examination revealed a superficial and deep perivascular and interstitial infiltrate consisting of lymphocytes, neutrophils, and eosinophils. Water samples contained many cnidarian larvae, later grown to maturity and identified as Linuche unguiculata (thimble jellyfish). Enzyme-linked immunosorbent assay demonstrated in patients' sera high IgG levels specific for L. unguiculata.


CONCLUSION
SE is a severely pruritic marine dermatosis that resolves spontaneously within 2 weeks. Therapy is symptomatic but often ineffective. Sera from affected persons showed specific reactivity to L. unguiculata.
Portuguese Man of War envenomization. A personal experience.
THE FOLLOWING is a description of a systemic reaction to the sting of a Portuguese Man-of-War; the sting occurred while I was on a training exercise with the 8th Special Forces Group SCUBA Team in Limon Bay, Canal Zone. Report of a Case While swimming at a depth of 15 feet, I felt a sudden severe stinging sensation on the right shoulder, as though a hot iron had been placed there. The shock of the contact was sufficient to bring about an involuntary jerking and thrashing in the water. Within seconds there began a sensation of tightness in the chest and a bilateral subcostal constriction. The burning in the shoulder spread rapidly to include the upper arm, and cramping began deep in the hypogastrium. Concurrently there were abdominal skeletal muscle spasms and waves of paresthesias of a tingling nature which started in the shoulder and moved over the body. Within