Cutaneous toxicity from fish ingestion

Author: Dr Lydia Chan, Dermatology Registrar, Dermatology Department, Auckland District Health Board, Auckland, New Zealand. DermNet New Zealand Editor-in-Chief: A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy Writer: Gus Mitchell. September 2017.


What skin signs can be seen as a result of fish ingestion?

Various syndromes that may affect the skin have been described after ingestion of fish or fish products.  These include:

A combination of the above can occur in the same patient. It can be difficult to differentiate the cause, as symptoms may appear similar.

Skin peeling due to fish poisoning

Scombroid fish poisoning

What causes scombroid fish poisoning?

Scombroid fish poisoning is caused by eating decomposing scombroid fish, such as kahawai, mackerel and tuna.  Bacteria in the decomposing fish produce various by-products including scombrotoxin, which contains histamine.

What are the clinical features of scombroid fish poisoning?

The clinical features of scombroid fish poisoning include:

What are the complications of scombroid fish poisoning?

Scombroid fish poisoning resolves without complications. In severe cases, symptoms may persist for several days.

How is scombroid fish poisoning diagnosed?

Scombroid fish poisoning is usually diagnosed from a clear history of onset of symptoms within one hour of eating a particular fish.

What is the differential diagnosis for scombroid fish poisoning?

The main differential diagnosis for scombroid fish poisoning is type 1 allergic reaction including anaphylaxis.

Scombroid fish poisoning can take minutes to induce a reaction. Other reactions due to fish ingestion tend to progress more slowly, over hours, days or weeks.

What is the treatment for scombroid fish poisoning?

The treatment of scombroid fish poisoning is rapid-acting oral antihistamines, which may resolve the symptoms within minutes.

The responsible decomposing fish should be discarded.

What is the outcome of scombroid fish poisoning?

Scombroid fish poisoning rapidly resolves. Patients can eat the same species of fish again, as long as it is stored in cold conditions to prevent bacterial decomposition.

Vibrio vulnificus infection due to seafood ingestion

What causes Vibrio vulnificus infection?

Vibrio vulnificus infection can follow consumption of contaminated seafood such as raw oysters. This infection may also contaminate open wounds exposed to warm seawater.

What are the clinical features of Vibrio vulnificus infection?

The clinical features of a Vibrio vulnificus infection due to eating contaminated seafood include:

  • Fever
  • Chills
  • Decreased blood pressure
  • Nausea
  • Diarrhoea.

What are the complications of Vibrio vulnificus infection?

Patients with Vibrio vulnificus infection may become very unwell and require hospitalisation.

How is Vibrio vulnificus infection diagnosed?

Vibrio vulnificus infection can be suspected in unwell patients if they have a history of eating contaminated seafood.

The bacteria can be isolated from blood, stool and/or wound cultures using a special medium.

What is the differential diagnosis for Vibrio vulnificus infection?

The differential diagnosis for Vibrio vulnificus infection includes:

  • Another form of systemic or local bacterial infection, such as pseudomonas
  • Allergic reaction (anaphylaxis) to seafood  
  • Gastroenteritis due to seafood contaminants  
  • Norwalk virus
  • Ciguatera
  • Other vibrio species, such as Vibrio cholera.

What is the treatment for Vibrio vulnificus infection?

Vibrio vulnificus infection is treated with antibiotics, such as doxycycline or a third generation cephalosporin.  

What is the outcome of Vibrio vulnificus infection?

The outcome of Vibrio vulnificus infection is usually good with prompt treatment. The infection may be fatal in up to 50% of patients that have pre-existing liver disease. It has been recommended that patients with liver disease do not eat raw shellfish.

Mercury poisoning due to fish ingestion

What causes mercury poisoning?

Mercury poisoning is due to ingestion of mercury, including mercury in fish. In New Zealand, high mercury levels are found in the following species of fish:

  • Cardinalfish
  • Dogfish (excluding rig)
  • Lake rotomahana trout
  • Lake trout from geothermal regions
  • School shark (greyboy, tope)
  • Marlin (striped)
  • Southern bluefin tuna
  • Swordfish.

What are the clinical features of mercury poisoning?

The clinical features of mercury poisoning tend to occur weeks to months after acute ingestion. Symptoms may include:

  • Tiredness
  • Loss of appetite
  • Light sensitivity
  • Generalised weakness
  • Painful extremities
  • Tremor
  • Changes in mood.

Skin signs may include colour changes in the hands and feet, with associated pain and itch. Hair loss and nail loss has been described. Excessive sweating and inflammation of the gums may occur.

What are the complications of mercury poisoning?

Complications of mercury poisoning include pain and colour change in the extremities and permanent loss of teeth from gum inflammation. Hair and nail loss may be slow to resolve.

If severe, patients may develop acute renal failure.

How is mercury poisoning diagnosed?

Mercury poisoning can be diagnosed from measuring levels of mercury in the blood.

What is the differential diagnosis for mercury poisoning?

The differential diagnosis for mercury poisoning is broad, as symptoms may be nonspecific.

  • Vitamin A toxicity may present with hair loss and nail loss.
  • Arsenic toxicity may present with changes to the hands and feet (eg, blackfoot disease from peripheral vessel occlusion).
  • Scurvy from vitamin C deficiency may present with an unusual rash and inflammation of the gums.
  • Various psychiatric illnesses, eg, depression with low mood and poor appetite.

What is the treatment for mercury poisoning?

The treatment of mercury poisoning includes supportive care, such as correcting any fluid and electrolyte imbalances.

Chelation with meso 2,3-dimercaptosuccinic acid may be used to prevent methylmercury uptake by erythrocytes (red blood cells) and hepatocytes (liver cells).

It is essential to avoid further exposure to mercury. Avoid eating the aforementioned fish species. Be aware that various herbal and traditional remedies may contain mercury.

What is the outcome of mercury poisoning?

Signs and symptoms of mercury poisoning gradually disappear once treatment is started, providing there is no further ingestion.

Acute vitamin A toxicity due to ingestion of fish

What causes acute vitamin A toxicity?

Acute vitamin A toxicity is caused by the ingestion of too much vitamin A. There are high levels of vitamin A in fish liver of various species, including:

  • Ocean perch
  • Reef / tropical fish in Bermuda (may not be carnivorous species)
  • Mediterranean greater amberjack
  • Lutjanid (Etelis carbunculus)
  • Grouper fish (Cephalopholis boenak)
  • Hapuka
  • Shark
  • Tuna
  • Seabass.

Vitamin A toxicity can also be due to:

  • Ingestion of meat or organs (especially liver) from mammals such as whales, seals and polar bear 
  • Ingestion of fish (liver) oil capsules.
  • Vitamin A analogues (oral retinoids such as isotretinoin and acitretin).

What are the clinical features of acute vitamin A toxicity?

Acute vitamin A toxicity results in redness of the skin, followed by desquamation (peeling), dryness and peeling of the lips, and dry eyes. Hair loss and nail thinning or loss may become apparent after some weeks.

Other features of vitamin A toxicity include headache, abdominal pain, nausea and vomiting.

What are the complications of vitamin A toxicity?

Severe overdose of vitamin A can lead to death.

Intake of high levels of vitamin A or other retinoids during pregnancy have been associated with birth defects.

How is vitamin A toxicity diagnosed?

Diagnosis of vitamin A toxicity is based on the patient’s signs and symptoms, and a history of ingestion of vitamin A or a retinoid. There is a poor correlation between toxicity and serum retinol levels, as it Vitamin A is rapidly metabolised to retinoic acid. Blood samples must be stored in the dark before analysis.

What is the differential diagnosis of vitamin A toxicity?

The differential diagnosis for vitamin A toxicity is broad, as symptoms may be nonspecific. When symptoms are associated with ingestion of fish, consider:

  • Mercury poisoning
  • If onset of symptoms are acute, scombroid fish poisoning.

What is the treatment for vitamin A toxicity?

The source of vitamin A should be avoided, including fish and various supplements, herbal or traditional remedies containing vitamin A.  

Vitamin A will be processed by the body over time. Fluid and electrolyte abnormalities due to vomiting should be corrected.

What is the outcome of vitamin A toxicity?

The outcome of vitamin A toxicity is good. Skin peeling settles over a few weeks as new skin cells are generated.

 

Related Information

References

  • Ardigier G, Drouet G, de Haro L. Poisoning after ingestion of Mediterranean greater amberjack liver: Hypervitaminosis A clinical feature [French]. Presse Med. 2010 Jul-Aug;39:833–4. Pubmed
  • Chiu YK, Lai MS, Ho JC, Chen JB. Acute fish liver intoxication: report of three cases. Changgeng Yi Xue Za Zhi. 1999 Sep;22:468–73. Pubmed
  • Clarkson TW, Magos L, Myers GJ.  The toxicology of mercury—current exposures and clinical manifestations.  N Engl J Med. 2003 Oct 30; 349:1731–7. Journal
  • Dewailly E, Rouja P, Schultz E, Julien P, Tucker T. Vitamin A intoxication from reef fish liver consumption in Bermuda. J Food Prot. 2011 Sep;74:1581–3. Journal
  • Eastaugh J, Shepherd S. Infectious and toxic syndromes from fish and shellfish consumption. A review. Arch Intern Med. 1989 Aug;149:1735–40. Pubmed
  • Grubb BP. Hypervitaminosis A following long-term use of high-dose fish oil supplements. Chest. 1990 May;97:1260. Pubmed
  • Hayman RM, Dalziel SR. Acute vitamin A toxicity: a report of three paediatric cases. J Paediatr Child Health. 2012 Mar;48:E98–100. Pubmed
  • Homma Y, Otani N, Ishimatsu S. A Case Report of Acute Vitamin A Intoxication due to Ocean Perch Liver Ingestion. J Emerg Med. 2015 Jul;49:15–7. Pubmed
  • Hwang DF, Lu CH, Lin WF. Species identification and vitamin A level in lutjanid fish implicated in vitamin A poisoning. J Food Prot. 2010 Apr;73:769–73. Pubmed
  • Ministry for Primary Industries. Mercury in fish. Jan 2016. Available at https://tinyurl.com/ychxc7eh

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