The American Academy of Dermatology outlines the following steps to perform a patch test:

  1. Apply the product to the skin: A person can apply a small amount of product to a quarter-sized area of skin. Ideally, choose an area that is not easily rubbed or washed away, such as the underside of the arm or the bend of the elbow.
  2. Apply the product as instructed on the packaging: A person needs to follow the instructions on the packaging and apply the product in the typical amount and thickness as they would when using it regularly. If the product requires washing off, like a cleanser, they need to leave it on the skin for around 5 minutes, or for as long as the instructions suggest, before removing the product.
  3. Repeat the above steps: A person needs to aim to perform the patch test twice daily, for 7 to 10 days. If no reaction occurs after 10 days, the product is safe to use going forward. However, some reactions can occur immediately or within 48 hours. As soon as a reaction develops, a person needs to gently wash the product off and discontinue using it.

Signs of a reaction include:

  • rash
  • itching
  • skin discoloration
  • swelling
  • blisters
  • stinging sensation

Anaphylaxis: Symptoms and what to do

Anaphylaxis is a severe allergic reaction that can be life threatening. The symptoms develop suddenly and include:

  • hives
  • swelling of the face or mouth
  • wheezing
  • fast, shallow breathing
  • a fast heart rate
  • clammy skin
  • anxiety or confusion
  • dizziness
  • vomiting
  • blue or white lips
  • fainting or loss of consciousness

If someone has these symptoms:

  1. Check whether they are carrying an epinephrine pen. If they are, follow the instructions on the side of the pen to use it.
  2. Dial 911 or the number of the nearest emergency department.
  3. Assist the person in moving from a sitting position to lying down. If they have vomited, turn them onto their side.
  4. Stay with them until the emergency services arrive.

Some people may need more than one epinephrine injection. If the symptoms do not improve in 5 to 15 minutes, or they come back, use a second pen if the person has one.

For mild reactions, a person can apply a cool compress or petroleum jelly to ease symptoms. However, for more severe reactions or if symptoms do not resolve, a person may need to speak with a dermatologist.

A dermatologist may recommend that a person undergo a patch test done by a healthcare professional. This involves placing a small amount of the potential allergen on the skin and covering it for 48 hours. The healthcare professional will then check the skin after 72 to 96 hours.

In addition to performing a patch test, a person can read the ingredient panel on the packaging to see if any ingredients they know they are allergic to are present. If an individual still has questions, they can contact the manufacturer.

Find a medical specialist in your area today.

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Sometimes, a medical specialist will be required to help diagnose, manage, or treat a healthcare condition.

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