Leaving permethrin cream too long

What Happens If You Leave Permethrin Cream On Too Long?

If you are using Permethrin cream, this article may be helpful. I will share my experience with Permethrin and provide information to help you decide if it’s right for you.

Firstly, let’s discuss how Permethrin works. It is used to treat scabies, a condition caused by tiny mites that infest and irritate the skin. Permethrin kills both the insects and their eggs. It can also be used for pubic lice and is available under different brand names like Elimite, Nix, and Acticin.

Next, I will provide a step-by-step guide on how to use Permethrin cream. Additionally, I have previously written a related post on Itchy Skin When Sweating that you may find helpful.

How to use permethrin cream?

When using permethrin cream, it’s essential to follow the doctor’s instructions carefully. Apply the cream only on the skin and avoid getting it in your mouth, nose, eyes, or vagina. If the cream accidentally enters your eyes, wash them immediately with water and seek medical help if irritation persists.

Leaving the cream on for too long can result in skin irritation, itching, and redness. To prevent this, wash the cream off after the recommended amount of time.

In the next section, I will provide more information on how to use permethrin cream for scabies treatment.

What happens if you leave permethrin cream on too long?

Possible side effects of permethrin cream include skin irritation, itching, redness, and swelling. These symptoms can worsen after treatment. Additionally, mild burning and stinging may occur. It’s important to speak with your doctor or pharmacist if any of these side effects persist or worsen.

In rare cases, some individuals may experience more severe allergic reactions to the medication. If you experience difficulty breathing, swelling of the face, tongue, or throat, or severe dizziness, seek immediate medical attention.

This document does not include all possible side effects, and others can occur. Check with the physician for additional information about side effects.

Let’s think of this scenario: What Happens If Permethrin Is Not Washed Off? Well, the answer to this question is given in the next section.

What Happens If Permethrin Is Not Washed Off?

not washing off permethrin

Permethrin is an anti-parasite medication. In addition, Permethrin treats head lice and scabies. It may also be used for other perspectives not listed in this guide.

But what happens if Permethrin is not washed off? You should not use this medication if you’re sensitive to Permethrin or chrysanthemums.

If Permethrin is not washed off for a long time or even after 14 hours, it may cause several side effects such as: 

  • Mild burning and stinging
  • Skin swelling
  • Skin redness
  • Skin rash
  • Itching

It can also cause short-term side effects in sensitive individuals, including eye, skin, nose, and throat irritation, including breathing problems.

Another thing you should know is: What is the dosage of Permethrin? Then, I will reveal the recommended dosage of Permethrin.

What are the dosages of permethrin?

  • Cream:5%
  • Liquid:1%
  • Lotion:1%

Dosage Considerations are Given as  Follows:


  • Cream: Apply to your head to toe, leave on for 9-14 hours, rinse; can reapply in 7 days if live insects reappear
  • The single application is curative

Head Lice and Nits

  • Lotion/liquid: apply to your washed hair, leave on 9-10 minutes, wash and clean out eggs; may repeat in 7 days if insects or nits still present
  • The single application is usually curative.

Scabies and Head Lice, Pediatric

skin rashes

Children under two months

  • Safety and effectiveness not established

Children over two months

  • Scabies: Apply the head to toe; leave on for 8-14 hours, clean; may reapply in 7 days if live insects reappear; single application curative
  • Head Lice and Nits: Apply lotion/cream to washed hair, leave on 9-10 min, wash and clean out nits and eggs; may repeat in 7 days if lice or nits still present; single application curative.

Along with this, here I am also speaking about precautions before taking Permethrin medication.


Inform your doctor or pharmacist if you are allergic to permethrin or have any other allergies before using this medication. This medication may contain inactive ingredients that can cause allergic reactions. Therefore, it is recommended to consult your healthcare provider for more information.

Frequent scratching of the skin and scalp can lead to bacterial skin infections. If you develop pus or redness on the skin, inform your doctor.

If you are pregnant, consult your doctor before using this drug, as it can pass into breast milk and harm the nursing infant.

Lastly, it is essential to be aware of any possible drug interactions when taking Permethrin.


permethrin interactions

Your pharmacist may be aware of all possible drug interactions and may be monitoring you for them. Do not stop or change the medicine dosage before checking with your doctor or pharmacist.

Before using this medication on your skin, tell your doctor of all prescription and herbal products you may use. This product may interact with other medications, making them less effective or causing unwanted side effects.

It’s important to take note that Permethrin products may not be safe for everyone. Some warnings for using Permethrin products include:

  • Do not use if you are allergic to Permethrin or chrysanthemums.
  • Avoid getting the cream in your mouth, nose, eyes, or vagina.
  • Do not use on infants under the age of 2 months without consulting a doctor.
  • Use with caution in people with liver disease or a history of seizures.
  • If you experience any signs of an allergic reaction, such as difficulty breathing or swelling of the face, seek medical attention immediately.


Permethrin products should be stored at room temperature between 59-77 degrees F (15-25 degrees C) and kept away from light and moisture. Do not store in the bathroom. Keep all medications out of reach of children and pets.

When you no longer need the medication or it has expired, consult your doctor, pharmacist, or local waste disposal company for safe disposal instructions. Do not dispose of it by flushing it down the toilet or pouring it down the drain, as it can contaminate the environment.

Frequently Asked Questions

Is Permethrin harmful to humans

Is Permethrin harmful to humans?

Permethrin is generally considered safe for human use when used as directed by a healthcare professional. However, excessive exposure to the medication can lead to skin irritation, itching, and redness. Additionally, if ingested or inhaled in large amounts, Permethrin can cause more severe symptoms such as headaches, dizziness, and difficulty breathing.

It is important to follow the dosage and usage instructions provided by your doctor or pharmacist and to avoid using Permethrin if you are allergic to it or any of its ingredients. As with any medication, if you experience any concerning symptoms, you should consult a healthcare professional immediately.

What is Permethrin used for?

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