Recurrent Mouth Ulcers and Canker Sores in Children

Younger children often get mouth ulcers as part of a viral infection, like herpes gingivostomatitis or hand foot and mouth disease. In older children, recurrent ulcers are often caused by canker sores or aphthous stomatitis.

Causes of Mouth Ulcers

Your child's age, duration of symptoms (how long the ulcers have been there), and other symptoms can help you and your pediatrician figure out what is causing your child's mouth ulcers:

  • Herpes gingivostomatitis is caused by the herpes virus that causes cold sores (herpes labialis). The first time a child gets get this infection they may have irritability, high fever, and small, painful ulcers on the child's gums and inside the mouth rather than the few lip sores seen with recurrence.
  • Hand foot and mouth disease is a viral illness that causes mouth ulcers. It is caused by the Coxsackie virus and children with this infection usually get small red ulcers in the mouth, on the palms of the hands (palms), and the soles of the feet. They sometimes also get a rash on their legs and buttocks.
  • Herpangina is similar to hand foot and mouth disease, except that the ulcers are just in the child's mouth. It is also caused by the Coxsackie virus.
  • Gingivitis and bacterial infections may cause mouth ulcers
  • Geographic tongue also called benign migratory glossitis, can look like a large ulcer, with a smooth pink or red area on the tongue with a raised border. It is not usually painful, though, and no treatment is necessary.
  • Oral ulcers can also be caused by trauma, as a side effect of chemotherapy, radiation and certain drugs, especially Stevens-Johnson syndrome.

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Hand foot and mouth disease
Hand foot and mouth disease. DermNet / CC BY-NC-ND​

Recurrent Mouth Ulcers

Recurrent ulcers can be more difficult to diagnose, treat, and prevent. Referral to a specialist, a dentist or dermatologist, and perhaps a biopsy of an ulcer is sometimes necessary.

Trauma, like from a dental appliance, sharp tooth, habitual cheek biting, are a common cause of recurrent mouth ulcers. In this situation, you would expect the ulcers to keep coming back in the same area.

Recurrent aphthous stomatitis is a common cause of recurrent mouth ulcers in children and adults. They are also called canker sores. Although sometimes thought to be caused by smoking, food allergies, stress, vitamin deficiencies, and local trauma, no specific trigger is found in most people.

Although most people with recurrent herpes infections (herpes simplex labialis) get the ulcers on the outside of their lips (cold sores or fever blisters), some get them inside too.

Recurrent mouth ulcers can also accompany many systemic disorders, such as:

  • Inflammatory bowel disease
  • Cyclic neutropenia: Recurrent, cyclical episodes of mouth ulcers, fever and neutropenia (low white blood counts)
  • Gluten-sensitive enteropathy
  • Periodic fever syndrome (PFAPA): In which children get episodes of fever, aphthous stomatitis, pharyngitis, and cervical adenitis every two to eight weeks.
  • Vitamin deficiencies: Including iron deficiency anemia, and folate, zinc, or vitamin B12 deficiency
  • Behcets syndrome: Includes aphthous stomatitis, recurrent genital ulcers, and eye lesions.
  • HIV


In most cases, symptomatic treatments are the main option. This might include acetaminophen or ibuprofen-containing pain medications.

Medications to coat the ulcers can also be helpful, such as antacids (Maalox or Milk of Magnesia), and dental pastes. A combination of Benadryl and Maalox is often popular.

Topical analgesics include 2% viscous lidocaine applied directly to the ulcers, diphenhydramine (Benadryl) elixir mouthwash, and benzocaine preparations, such as Anbesol or Orajel Mouth-Aid.

Antiseptics, such as chlorhexidine gluconate (Peridex) and cetyl peridium chloride solution (Cepacol) might also be effective treatments when used as a mouthwash twice a day. Aphthasol (amlexanox) is an anti-inflammatory paste that can be applied to ulcers two to four times a day to make them less painful and help them heal faster.

Steroids are also sometimes used to treat oral ulcers. When needed, 0.1% triamcinolone acetonide (Kenalog) can be added to an emollient dental paste, like Orabase, and applied to the ulcers several times a day. Topical high-potency steroid gels are also sometimes used.


If a specific trigger for your child's oral ulcers is found, those things should be avoided. A symptom diary, recording when your child got the ulcer, the things they ate and used in their mouth (toothpastes, mouthwashes, etc.) just before, and any medications they may have taken, may help you find triggers.

When no trigger is found, a mouth rinse or toothpaste with triclosan may be helpful. Colgate Total toothpastes contain triclosan.

Sodium lauryl sulfate (SLS), which is an additive in many brands of toothpaste and mouthwashes, is thought to be a possible trigger of ulcers in some people with recurrent aphthous stomatitis. It may be helpful to use SLS-free products. SLS-free toothpastes include Biotene and Rembrandt's Canker Sore toothpaste.

It may also be helpful to use a soft toothbruch, avoid letting your mouth get dry, and avoid eating sharp foods like pretzels.

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6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Goldman RD. Acyclovir for herpetic gingivostomatitis in childrenCan Fam Physician. 2016;62(5):403‐404.

  2. Chansaenroj J, Auphimai C, Puenpa J, et al. High prevalence of coxsackievirus A2 in children with herpangina in Thailand in 2015Virusdisease. 2017;28(1):111‐114. doi:10.1007/s13337-017-0366-8

  3. American Osteopathic College of Dermatology. Geographic tongue.

  4. NIH National Center for Advancing Translational Sciences. Cyclic neutropenia. Updated May 18, 2016.

  5. Massachusetts Dental Society. Mouth sores.

  6. Altenburg A, El-Haj N, Micheli C, Puttkammer M, Abdel-Naser MB, Zouboulis CC. The treatment of chronic recurrent oral aphthous ulcers. Dtsch Arztebl Int. 2014;111(40):665–673. doi:10.3238/arztebl.2014.0665