Phytophotodermatitis is a rare type of chemical skin reaction that happens when chemicals on the skin are exposed to sunlight. The chemical that causes this reaction is called furocoumarin. 

Furocoumarin can be found in citrus fruits or plants like: 

• limes 
• lemons 
• oranges 
• mandarins 
• grapefruit 
• bergamot. 

When the juice or oil from these fruits gets on the skin and then is exposed to sunlight, it reacts and can cause irritation.  

The condition is more commonly known as "margarita burn" because the reaction can occur when limes are squeezed to make a margarita drink outside. 

Phytophotodermatitis can affect any part of the skin. Children with more sensitive skin are at a higher risk.  

While phytophotodermatitis is rare, it can be serious and very painful, especially for children.  

The symptoms of margarita burn can range from mild to severe and are similar to that of a sunburn. These can include: 

• skin inflammation 
• skin redness 
• skin discolouration 
• a burning feeling 
• pain 
• itching 
• blistering 
• skin loss. 

Symptoms generally begin 24 hours after exposure to the chemical in combination with sun. Symptoms usually peak after 2-3 days.  

Your child’s doctor can diagnose phytophotodermatitis based on signs and symptoms, their recent activities, and a physical examination of the skin.  

Depending on the severity, your child may be referred to their local hospital, dermatologist or burns unit for treatment and dressing. 

The treatment that your child will receive will depend on the severity of the injury. 

Treatment options may include: 

• a cold compress to help the pain 
• pain relief 
• dressing the blistered area. 

It is important to keep the injured area out of the sun and to seek medical treatment.