More than 500 fishermen have been hit by a mysterious skin disease after returning from the sea.
The workers contracted the strange contagious condition in the West African country of Senegal when they were back on dry land.
They were left with lesions on their faces and, in some cases, on their genitals.
The fishermen, from various fishing towns around the capital Dakar, have been quarantined for treatment.
A first case was reported a week ago.
Images shared on social media showed men with swollen and blistered lips and large pimples on their hands.
Officials scratched their heads over the cause.
A senior government health official in the country confirmed the puzzling situation on Thursday.
Ousmane Gueye, National Director for Health Information and Education, said: “It’s a dermatitis linked to an infectious disease.
“We are looking further and hope to find out what it is soon.”
The Senegalese Navy will be sent to take water samples for analysis.
A report from the Ministry of Health on Nov. 17 stated that the men had “lesions on their faces, limbs and for some on their genitals.”
The document stated that the men also had headaches and showed slightly elevated temperatures.
A preliminary investigation showed that the first case was reported on Nov. 12, involving a 20-year-old fisherman.
He exhibited symptoms including non-generalized vesicular rash, facial swelling, dry lips and redness of the eyes.
The outbreak of the disease is said to have caused fear among health officials.
It comes from poisonous products that, according to reports, were dumped on the shore by an unidentified boat between the cities of Dakar and Mbour.