What causes scabs?

Scabs are a common symptom of skin infections, immune-mediated skin disorders, and injury. Scabs result from a growth of new skin over damaged skin as your skin attempts to heal.

Wounds or scratches due to viral skin infections, including cold sores (herpes simplex), chickenpox (varicella zoster), or shingles (herpes zoster), are common causes of scabs. Blisters, lacerations, abrasions or burns may also cause scabs as they heal. Impetigo, a bacterial skin infection, can also result in scabs.

Traumatic causes of scabs

Scabs may be caused by injury including:

  • Abrasions
  • Blisters
  • Burns
  • Insect bites
  • Lacerations
  • Lesions

Disease causes of scabs

Scabs can also be caused by certain disease conditions including:

  • Atopic dermatitis (eczema)
  • Bacterial skin infection (impetigo)
  • Chickenpox blisters or shingles (varicella zoster virus)
  • Cold sores on your mouth and lips (Herpes simplex virus)
  • Dermatitis artefacta (self-inflicted sores)
  • Pemphigus vulgaris, fluid-filled blisters on your skin and mucus membranes (autoimmune disorder)
  • Psoriasis lesions (immune disorder)

Serious or life-threatening causes of scabs

In some cases, scabs may be a symptom of a serious bacterial skin infection that should be immediately evaluated in an emergency setting. These include abscess and serious infection.

Questions for diagnosing the cause of scabs

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your scabs including:

  • Where do you have scabs?
  • When did you first notice the scabs?
  • Do you have scabs frequently?
  • Do you have any other symptoms?
  • What medications are you taking?

What are the potential complications of scabs?

Because scabs can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

  • Scarring
  • Secondary bacterial infection
  • Spread of infection


  1. First aid: Cuts, scrapes and stitches. FamilyDoctor.org. http://familydoctor.org/online/famdocen/home/healthy/firstaid/after-injury/041.html.
  2. Vesicles. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003939.htm.

What are scabs?

Scabs are a common symptom of skin infections, immune system skin disorders, and injury. Scabs result from the healing process, in which new skin grows over damaged skin. They may occur in conditions affecting one area of skin alone, or along with more generalized conditions, such as shingles, chickenpox, or eczema. Only i... Read more about scabsintroduction


What other symptoms might occur with scabs?

Scabs may accompany other symptoms, which will vary depending on the underlying disease, disorder or condition. Symptoms that frequently affect the skin may also involve other body systems.

Skin symptoms that may occur along with scabs

Scabs may accompany other symptoms affecting the skin including:

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 20, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Infections and Contagious Diseases

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