Fire coral dermatosis Fire coral persi,stent • cutarieous reactwn M.Paradisi, A. Grassi, G. Conti, F. Passarelli and M.G. Cacciaguerra SUMMARY A patient who developed a persistent cutaneous reaction to fire coral is presented. Treatment with topical corticosteroids reduced the severity of the lesion but after a follow-up period of 18 months no complete resolution has been showed. Introduction Red Sea Coral ("stinging" or "fire coral") is a coelen- terate of the Milleporina order and of the Hydrozoan class. It derives its name because it releases nematocysts, toxic organelles responsible for cutaneous lesions , immediately att:er contact with skin. All coelenterates are invertebrate organisms com- posed of a double epithelial layer, which delimits a ca- vity, the "coelenterium". Their venomous apparatus is composed of the nematocysts, toxin-releasing organe- lles composed of a capsule and tube, located in large numbers on the tentacles and made-up of collagen-like material. The venom is ejected by the capsula of the nematocyst through the long filamentous tubule into the victim's body (1). Toxic substances in the venom include quaternary ammonium compounds, proteins, 5-hydroxytrypta- mine, catecholamines, histamine and histamine libe- rators. The cutaneous lesions are induced by the toxic substances liberated and by the foreign-body reaction to the fragments of calcium carbonate, which are in the tentacles that hurt the skin (2). Moreover, the skin scars are accompanied by burn and/ or pain. The severity of the cutaneous reactions depends on the number of the nematocysts discharged, the venom toxicity, the intensity of the stinging and the in- dividual sensibility (3). The general symptoms, which have been reported, include nausea, vomiting, abdo- minal pain, diarrhea, muscle spasm, respiratoty diffi- culty, tachycardia, hypotension and fever (1,4). In the majority of cases soon after the contact with the fire coral an erythematous reaction appears, which spontaneously heals in about two months. Sometimes there is a lesional polymorphism. Soon after contact to a fire coral an acute vesiculo-bullous dermatitis follows; then there is a subacute granulomatous dermatitis and, Case report 20 ----- ------------------------------Acta Dermatoven APA Vol 10, 2001, No 1 Fire coral dermatosis C a s e rep o rt in the last phase, a chronic lichenoid dermatitis. r Some authors have described a delayed or recurrent · gfranulomatodus-lfike or sar 2 coid-likhe cfutanehousfreaction 1 _ a ter a perio o up to 1 mont s rom t e ire cora ~ contact (5) . In some patients the coelenterate's induced cutaneous reaction can be delayed by the use of systemic corticosteroids (6). Case report A 41 -year-o ld man with a personal history of gastroduodenitis came to our observation in September 1996 for an eczematous lesion on the right arm. He referred that during the month of July, while swimming off the Red Sea, he had touched a coral well known as "fire coral" w ith his right arm (Fig. 1). Imme- diately an acute e1ythematous and edematous dermatitis with burning and pruritus developed on the site of contact. Under antihistaminic therapy he noticed a marked reduction of the edema soon after 3 days, but the ecze- matous dermatitis persisted even under topical therapy with betamethasone dipropionate. When the patient presented to us we noticed an erythematous-infiltrated, well-demarcated, 25X5 cm plaque, on the lateral surface of the right arm. A biopsy of the lesi on showed a dense perivascular infiltrate composed by lymphocytes, histiocytes and some eosinophils in the papillary and mid dermis. Superficial blood vessels were slightly dilated (Fig. 2). Histiocytes were mixed together w ith lymphocytes; there was no granuloma formation. The epidermis showed a slight ortho- and parakeratosis and some neutrophils in the stratum corneum. Immunohisto- chemical stucly revealed a T phenotype of all lympho- cytes. Because of the gastrocluodenitis the patient receivecl no systemic steroicls but only topical application of clobetamethasone dipropionate twice a day, on alter- nate weeks for two months. The skin lesions healecl only partially with persistence of the lesion up to the next four months. Discussion With this report we want to stress the characteristic of the cutaneous lesions inclucecl by the "fire coral" clue to the poor attention received in the clermatologic lite- rature . It has been observed that while the cutaneous lesi- ons which appear soon after the contact with the "fire coral" depencl on the venom toxicity, the clelayed or recurrent lesions could be caused by a clelayecl hyper- sensitivity response to an antigenic compound of the Figure 1 . Fire coral, a coelenterate of the milleporina order. It has a protective calcareous skeleton with powerful stinging cells or nematocysts that release toxins. x 2. Figure 2. A perivascular infiltrate of lymphocytes, histiocytes and eosinophils in papillary and mid dermis. HE x 40. -~ 1 : }, r. .,-.: : -✓ ' 1, •.~,... - , .,,,,,,..:, ,· ... 22 ------- ---------- -----------------Acta Dermatoven APA Vol 10, 2001, No 1 Case report Fire coral dermatosis coelenterate's nematocyst. Some authors propose a type I hypersensitivity associated with a type IV allergy (7). or ulcero-necrotic reaction associated or not to anaphi- laxys, a leukocytoklastic-like vasculitis and, in many of these latter cases, a delayed response of type IV. Most probably our case can be included into this last group. An immunohistochemical study reveals that Langer- hans cells and T lymphocytes may play a role in the cutaneous eruptions to coelenterates (8). In particular, in our case the histologic studies sho- wed a chronic unspecific dermatitis without granuloma and almost without epidermal changes. Ali these