noticeable or it may consist of a faint erythematous and miliary irritation. A second variety of envenomation
consists of a delayed papular, hemorrhagic, or zosteriform reaction with onset 4 to 12 hours after contact.
Rarely, erythema multiforme or a desquamative eruption may develop. In turbulent waters or in a strong
current, fragments may be washed into a diver's mask or regulator mouthpiece; this will be evident as a
burning sensation in the conjunctivae or oral mucous membranes. Systemic manifestations (such as
abdominal pain, nausea, vomiting, diarrhea, muscle cramps, and fever) are rarely reported and are associated
with large areas of surface involvement. Allergic sensitization and subsequent anaphylaxis have been
proposed.
Treatment. The skin should be rinsed with seawater and gently dried without abrasive activity.
Application of fresh water and brisk rubbing are strictly prohibited because they encourage any nematocysts
remaining on the skin to discharge and thus worsen the envenomation. Acetic acid 5% (vinegar) or isopropyl
alcohol 40% to 70% has been traditionally recommended for application to the skin for 15 to 30 minutes to
relieve the cutaneous reaction. In an in vitro evaluation, vinegar and urine caused discharge of a few
nematocysts in 10% to 15% of defensive tentacle polyps; methylated spirits were found to cause gross
discharge of microbasic mastigophores in all defensive polyps. Fresh water did not cause discharge. On the
basis of this study the authors recommended that freshwater irrigation and the application of ice be used to
treat acute stings. However, the clinical correlation remains to be described.
Alternative topical agents are discussed in the larger discussion on therapy for coelenterate stings.
After pain relief is achieved, a mild steroid cream (hydrocortisone 1%) or moisturizing lotion may be applied.
Fire coral. The stony, hydroid, and coral-like Millepora species (for example, M. alcicornis), or fire
corals, are not true corals. They are widely distributed in shallow tropical waters. Sessile creatures, they are
found attached to the bottom in depths of up to 1000 m. They are often mistaken for seaweed because they
attach to pilings, rocks, shells, or coral. Although smaller segments resemble Christmas trees or bushes 3 to 4
inches in height, they may attain heights of 2 m. The color ranges from white to yellow-green, with pale
yellow most common. Rare purple fire corals exist. Fire coral is structured on a razor-sharp lime carbonate
exoskeleton, which is an important component in the development of coral reefs. The outcroppings assume
upright, clavate, bladelike, honeycomb, or branching calcareous growth structures that form encrustations
over coral and objects such as sunken vessels. From numerous minute surface gastropores protrude tiny
nematocyst-bearing tentacles, wherein lies the stinging apparatus. M. alcicornis probably accounts for more
coelenterate envenomations than any other species. Unprotected and unwary recreational scuba enthusiasts
handle, kneel, or lean on this marine stinger.
CLINICAL
ASPECTS.
Immediately after contact with fire coral, the victim suffers burning or
stinging pain, with, rarely, central radiation. Intense and painful pruritus follows within seconds, which
frequently induces the victim to rub the affected area vigorously, worsening the envenomation. Over the
course of 5 to 30 minutes, urticarial wheals develop, marked by redness, warmth, and pruritus. The wheals
become moderately edematous and reach a maximum size in 30 to 60 minutes. Untreated, they flatten over 14
to 24 hours and resolve entirely over 3 to 7 days, occasionally leaving an area of hyperpigmentation that may
require 4 to 8 weeks to disappear. The pain generally resolves without treatment in 30 to 90 minutes. In the
case of multiple stings, regional lymph nodes may become inflamed and painful. This does not necessarily
indicate a secondary infection. Long thoracic mononeuritis with serratus anterior muscle paralysis has been
described after Millepora sting, confirmed by demonstrated presence of immune-specific IgG.
TREATMENT. The skin should be rinsed liberally with seawater and then immediately soaked with
acetic acid 5% (vinegar) or isopropyl alcohol 40% to 70% until pain is relieved. Alternative topical agents are
discussed in the larger coelenterate treatment section. Residual dermatitis is generally not very severe and can
be managed in a fashion similar to that following a feather hydroid sting. If the rash becomes eczematous and
indolent, it may respond to a course of systemic corticosteroids (prednisone 60 to 100 mg, tapered over 2
weeks). Divers should avoid touching with bare skin anything resembling coral. For instance, the underwater
statue of Jesus at John Pennycamp Park in Key Largo is encrusted with fire coral, so posing divers are have
been envenomed.
Physalia (Man-of-War). The Atlantic Portuguese man-of-war (Physalia physalis) of the phylum
Coelenterata, order Siphonophora, is a pelagic (open sea) polymorphic
