A 7-year-old boy presented with itchy rash over left knee for two days, which started following swimming in the sea. He was otherwise healthy. The parents of the child revealed that he developed itching while he was swimming in sea along the beach side (Dammam, Saudi Arabia) followed by appearance of reddish skin lesions the next day On cutaneous examination, There were four linear L/V-shaped erythematous plaques with edematous margins on the four corners of a crossway forming a star shaped pattern over right knee [Fig. 1]. No skin lesions were noted elsewhere on the body. There was no history of systemic symptoms like nausea/vomiting/dizziness/numbness of affected limb. There was no evidence of any spicule/foreign body over skin lesions in the affected limb. Hence, the case was diagnosed as contact dermatitis/aquatic dermatitis caused by marine flora/fauna possibly by blubber jelly fish (Catostylus mosaicus) which is seen in the shallow and warm coastal area near eastern province of Saudi Arabia. He was prescribed topical fluticasone propionate 0.05% cream and oral antihistamines. After seven days, the rash resolved completely.

Figure 1.

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The blubber jelly fish (Catostylus mosaicus), [Fig. 2] also known as the blue blubber jellyfish or Jelly blubber, is a species of jellyfish found in the coastal regions of Indo-Pacific. In Australia, it is found in the coastal areas of New South Wales, Queensland and Victoria. Large swarms have been seen in estuarine waters. In Saudi Arabia it has been reported from Half moon bay beach in Arabian Gulf. It is also present in the shallow coastal waters southwards to Abu Dhabi in United Arab Emirate and Tanzania. The color of the jelly blubber's large bell varies from creamy white to brown or blue. There are two types of stinging cells in their tentacles namely spirocysts and nematocysts. These inject three toxins canhypnotoxin, congestin and thalaxin into the prey. Hypnotoxin causes anaesthetic effect and paralyzes the prey. Congestin causes paralysis of respiratory and circulatory systems of the prey. Thalaxin causes allergic reaction leading to inflammatory dermatitis.

Figure 2.

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