Why Do Burns Itch? A Guide to Post-Burn Pruritus and Itch Relief

This post is a continuation of the series on burns.
Previously covered topics are:
Burn injuries at home- prevention, action, and home care.
Burns first aid at home.
What are the different degrees of burns? Understanding burns classification.
How to reduce burn scars? Top 10 ways to heal burn scars at home.
Essential safety tips for Diwali to prevent burns and injuries.

Post-burn itchiness or post-burn pruritis, as it is medically called, occurs commonly during the healing process of burn wounds. Although it is a benign condition, it can negatively impact the quality of life by disturbing sleep or making it hard to concentrate at work or your daily activities.

Read on to find out why do burn scars itch and what can you do about the post-burn pruritis.

Why do burn scars itch?

Unlike the usual skin itching, in which locally produced histamine plays a role, it plays a minimal role, if any, in the itchiness of burned skin.

As to the reason of post burn pruritis, The precise mechanism that leads to itching is not yet known. It is believed that the central nervous system regulates the itching in burns. This could explain why it responds poorly to anti-histaminic and better responds to medications that act on the central nervous system.

How common is post-burn itching?

Post-burn pruritis or itchiness typically occurs as the wound starts to heal and occurs within a few days of the burn. The prevalence has been reported as anywhere in 60 to 100% of burn cases studied.

The intensity can range from mild to severe, intractable itching that results in incessant scratching, leading to wounds on the burn scar and impacting the quality of life.

The itching is more commonly seen with:

• Larger burn areas.
• Deeper burn injuries. (Read: What are the different degrees of burns?)
• Burn injuries with raised or thick scars. (Read: Top 10 ways to heal burn scars at home.)
• Cases that experienced early post-traumatic stress.
• History of surgery for burns.
• Women.
• Burns of the arms or legs, and less commonly with facial burns.
• Certain environmental factors like heat and humidity can also intensify the itchiness.

How long does a burn itch last?

There is no definite timeline regarding how long the itchiness will last.

It can start anytime as the wound starts to heal and continue as the scar production happens, which can be years from the initial injury.
Furthermore, if the patient needs surgery, it can exacerbate or restart the itching.

However, itching becomes significant after about one month of burns, peaks at six months, and starts to decline by one year (Ahuja).

Is there anything I can do to avoid the itching?

Factors such as the extent and depth of burns and gender are beyond one’s control.
However, a good after burn care can ensure that the burn depth does not increase, making it was essential that you seek help from a medical professional in case of burns.
Others, like the environment, may be controlled to some extent.

Fortunately, itching tends to decrease with time.
In the meantime, there are treatments available to make you more comfortable.

How do I treat my itching?

Scratching is the first thing that one ends up doing to an itch. However, it is not a practical solution as it can damage the skin.

It is important to understand the following facts about managing itchiness in burns:

1. There is currently no single best treatment available.
2. No treatment will stop the itching completely.
3. A single agent is often ineffective; generally, a combination of therapies is needed to relieve the distressing itch.

The options available for managing post-burn itching are:

1. General measures
2. Topical therapy
3. Oral medications.
4. Alternative therapy.

General measures

• Keep the scar well moisturized. Dry skin will exacerbate the itchiness. This is a very important step in after-burn care and should not be missed.
• Cooling the cream in the fridge before application and massaging it rather than just applying it topically is also helpful.
• Wear cotton clothes. Cotton keeps the body cool; synthetic clothing will irritate the skin.
• Heat and sweat can increase itching, so try to avoid such environments.
• Use only unscented products for laundry or skincare.
• Protect your skin from sun exposure by wearing sunscreens and wearing appropriate clothing (hats, full-sleeve shirts, etc.)
• Custom-made pressure garments might help with not just the scar treatment but also with the itchiness.
• In the case of children, short fingernails and use of mittens can reduce injury to the fragile burned skin.

Topical therapy

Creams and lotions

• Moisturize, moisturize, moisturize. This is the basic and most widely used treatment.
• Colloidal oatmeal is an effective moisturizer in burn scars, probably due to forming an occlusive barrier that increases the hydration level on the scar.
• Cooling agents like menthol and camphor can temporarily mask the sensation of itching.
• Local anesthetics like topical lidocaine ointment may help to a certain degree. However, it should ne be applied only under medical supervision and only to a small area of healed burned to reduce the chances of systemic toxicity.
• Doxepin, a prescription cream, has shown some success, but it is still not a established treatment. This is used only in fully healed burn wounds not exceeding 20% of the body surface area.

Baths

• Colloidal oatmeal baths may be beneficial in some, especially when combined with a post bath oatmeal cream.
• Hot water baths can dry out the skin and increase itching.

Oral medications

Antihistaminics like Benadryl, Atarax, and Cetrizine, are the most commonly used oral medications for itching in burns. However, studies have shown that they do not provide complete relief, with one study showing that it helped only 20% of patients.

Gabapentin (Neurontin) is a prescription medication with a central action, i.e.on your brain, and has shown promising results in many case studies.

Others

• Laser therapy has been found effective in certain studies. However, this is not a well-established modality.
• TENS therapy (Transcutaneous electrical nerve stimulation) involves the controlled application of low-voltage electrical impulses to the skin and is commonly used in the management of muscle pain. A pilot study involving 20 adult burn patients with severe pruritus demonstrated
  a significant relief compared with placebo over 3 weeks..
• Alternative therapies like acupuncture, hypnosis, and meditation have been tried that help the patient to focus on something else other than the itching sensation.

Takeaway

• Burn scar itching can occur in up to 100% of cases.
• The exact mechanism is not yet defined but is believed to originate from the central nervous system and not locally from the skin.
• Itching can last anywhere from a few months to years and is more common in burns of the arms and legs.
• No current best single treatment is available, and in most instances, a combination of therapies is needed.
• General measures like wearing cotton clothes and keeping the skin well moisturised are combined with medications like oral antihistamines or gabapentin are a usual way of managing the itch.