A rare case of irritant dermatitis due to exposure to sargassum in Puerto Rico

Algal dermatitis is a little-studied problem that has been gaining more and more relevance in Puerto Rico. Check out what is going on there.

A rare case of irritant dermatitis due to exposure to sargassum in Puerto Rico
The municipality of Guánica requested help from the DNER to clean up the sargassum on Playa Santa. Image: El Vocero

Despite the importance of marine algae for the environmental ecosystem, some species can have potentially harmful effects on human health. Algal dermatitis is a little-studied problem that has become increasingly relevant, especially in the region of Puerto Rico and the Caribbean.

Dermatitis due to contact with algae can be caused by different species of algae, but especially Lyngbya majuscula. Less frequently, it can be caused by Sargassum. Lyngbya majuscula is a blue-green algae that releases dermatotoxins, lyngbya toxin A, and debromoaplisiatoxin, and is usually present in saltwater.

It can cause a rash that spreads from minutes to hours after exposure and is characterized by a stinging, itching, and burning rash, followed by pustules and peeling skin that may cause headache and fatigue.

Although it usually resolves within a week, exposure of bathers to this type of algae can represent a health problem due to its high levels of toxic components such as iodine, hydrogen, sulfur, and ammonia, especially when it decomposes.

Precisely one case occurred on the island, in an 11-year-old boy, with an urticarial, pruritic, hyperemic, and hyperthermic rash, after being exposed to sargassum on a beach in the country.

Arm of patient affected by algal dermatitis.
Arm of patient affected by algal dermatitis. Photo: Provided by the researchers.

The authors of the case describe that the exanthema presented by the pediatric patient is different from the few described in the literature. The treatment for the diagnosis of algal dermatitis caused by the sargassum species was based on steroids and antihistamines.

Sargassum toxicity is becoming a relevant issue in the Caribbean due to the massive rafts that accumulate in bodies of water and the dermatological, neurocognitive, and physical constitution effects that have been reported in bathers exposed to the accumulation of seaweed.

"Measures should be taken to prevent and raise awareness about this type of consequences among bathers water filled with sargassum containing more research is needed to deepen the knowledge of this condition and its implications on human health," concludes the case.