Medical Advice

Medical Advice

Skin Injuries from Marine Life


True Jellyfish & Portuguese Man-of-War Stings: The phylum Colenterata — are hollow bodied animals often equipped with stinging units called nematocysts. Phylum Colenterata contains the class Hydrozoa (Portuguese Man-of-War) which is a separate class from Scyphozoa (true jellyfish). The severity of jellyfish and Portuguese man-of-war stings are variable. Since the nematocytes are located at frequent interval along the length of the tentacle, the exposure length of tentacle involved is a good measure of the number of stings delivered.

Symptoms of Hydrozoa & Scyphozoa Stings:

  • Painful raised re lesions (papules) in lines (consistent with contact with the tentacle).
  • Muscle spasms may develop in the affected extremity.
  • The raised red lesions may develop into fluid filled lesions (vesicles) and may heal with pigmentation.
  • With extensive or repeated exposures systemic reactions can take place, such as; nausea, vomiting, headaches, dizziness (vertigo), muscle weakness and irregular heart rate (arrhythmias) may occur.
  • Other symptoms like, excessive tearing, runny nose and painful breathing (pleuritic chest pain).

Treatment of Hydrozoa & Scyphozoa Skin Injuries:

  1. First remove any adherent tentacles that will cause further delivery of venom. The tentacles should be lifted off the skin (don’t scrape them off – this causes further strings). Use a stick or some other object to remove the tentacle(s) so as not to get your fingers stung.
  2. Next, rinse the affected area with sea water to wash away any adherent nematocysts. DO NOT use fresh water, since this will activate the nematocysts. DO NOT scrub as this will only activate the nematocysts and cause further venom delivery.
  3. Nematocysts are inactivated by vinegar (or dilute acetic acid 5-10%). NOTE: If no vinegar is handy, then human urine will do in a pinch. If you have a choice in the matter, use a man’s urine rather than a woman’s urine. This is because females are more prone to occult urinary tract infections, thus introducing bacteria. Male urine is considered sterile, since men are much less likely to have a urinary tract infection.
  4. If there are any nematocyst still adherent after rinsing with sea water and inactivation with vinegar/urine, then try the following to remove any remaining nematocysts:
    1. Dust the area with backing powder, or flour, then carefully scrape off with the dull back edge of a butter knife…
    2. Or use aerosol spray shaving cream to coat the area, then shave off any remaining nematocyst.
  5. Symptoms of pain can be treated with topical anesthetics; these are generally contained in sunburn preparations; look for the active ingredients like lidocaine or benzocaine.
  6. Persistent redness, inflammation or itchiness can be treated with topical steroid cream like Hydrocortisone 0.5% cream.
  7. If you begin to develop persistent muscle spasms, seek medical attention; your doctor will need to administer intravenous calcium gluconate.
  8. Secondary bacterial infection may set in, especially if vesicles from. If this happens you will need to see a doctor for antibiotics.