Clinicians on Lampedusa identified 82 migrants with severe acquired methaemoglobinaemia at disembarkation between March 2024 and December 2025. Most were young men. The coordinated investigation was published in NEJM in September.
Median methaemoglobin at presentation was 44.6%, and 43% had 50% or more. Methylene blue was used in 90%, often repeatedly. Delayed haemolytic anaemia developed in 38 patients, often needing transfusion, and two died. N-methylaniline, a petrol additive, or its metabolites were found in 37 of 39 tested patients and at 1.1% in fuel from one vessel. Dermal absorption from fuel-contaminated seawater was the likely route.
The lesson travels beyond migration: prolonged skin contact with fuel can cause life-threatening methaemoglobinaemia, and haemolysis can follow days later.
- Suspect methaemoglobinaemia with cyanosis and low pulse oximetry unresponsive to oxygen.
- Ask about skin exposure to fuel or industrial chemicals.
- Check methaemoglobin on co-oximetry; treat with methylene blue where indicated.
- Screen for G6PD deficiency before methylene blue where possible, and monitor for delayed haemolysis.
Why it matters
Dermal fuel exposure is an under-recognised cause of fatal methaemoglobinaemia with a delayed haemolytic phase.
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