Urticaria is a common skin condition characterised by well-circumscribed, intensely pruritic, oedema of the superficial skin, typically one or two cm in diameter, although they can vary in size and coalesce to form a large raised wheal.1 Urticaria can occur on any part of the skin1 and is more often acute than chronic.2

What causes urticaria in infants?

The most common causes of acute urticaria in infants include food allergens, such as cows' milk protein. Insect bites, medication or infection can also result in urticaria.1 The possible causes of urticaria can often be identified in infants with acute urticaria, although the specific trigger can only be found in 10–20% of chronic cases. 3

Urticaria as a symptom of Cows' Milk Allergy
Urticaria is one of the many cutaneous symptoms of Cows' Milk Allergy (CMA).4  Urticaria with angiodema been reported to occur as a symptom of CMA in almost 30% of infants and usually appears as early reaction to the ingestion of cows' milk protein.5,6

The majority of infants affected with CMA have at least two symptoms affecting at least two different organ systems.4,7  If you suspect non-IgE mediated CMA, you can use the CoMiSS® tool 11 to score the combination of their symptoms and assess the likelihood of CMA.

Other signs and symptoms related to CMA8,9,10
  • Gastrointestinal/Digestive: Vomiting, reflux, regurgitation, anorexia, diarrhoea, constipation, abdominal pain, blood in stools
  • Respiratory: Chronic cough, sneezing, wheezing, shortness of breath, runny nose
  • Skin: Rash, atopic dermatitis, urticaria, angioedema
  • General: Failure to thrive, anaphylaxis, insomnia, inconsolable crying, pallor and tiredness
Baby with hives

How to score this symptom with the CoMiSSTM tool
  • The presence of urticaria is scored: no=0, yes=6
  • In addition to the skin symptoms score, if any of the following signs or symptoms related to CMA are present, they should also be given a score using the CoMiSSTM tool. These include crying, diarrhoea, constipation, regurgitation, skin (atopic dermatitis) and respiratory symptoms


The Cows' Milk-related Symptom Score (CoMiSSTM) is a simple, fast and easy-to-use awareness tool designed to help you more easily recognise the signs and symptoms that can be cows' milk-related in infants and young children.


If you suspect your patient is suffering from symptoms that may be suggestive of CMA, use the CoMiSSTM tool to score and assess the likelihood of CMA.

Other Symptoms of Cows' Milk Allergy


  1. Schaefer P. An Fam Physician 2011 May 1;83 (9): 1078-84
  2. Deadcock SJ. Clin Exp Immunol. 2008;153(2):151-61
  3. Kulthanan K., et al. J Dermatol. 2007;34(5): 294–301
  4. Lifschitz C and Szajewska H. Eur J Pediatr. 2015;174:141–50
  5. Hill DJ., et al. Clin Allergy 1988;18(5)481-90
  6. Vandenplas Y., et al Arch Dis Child 2007;92:902-08
  7. Høst A. Pediatr Allergy Immunol. 1994;5:1–36
  8. Koletzko S., et al. J Pediatr Gastroenterol Nutr. 2012;55(2):221–9
  9. Luyt D., et al Clin Exp Allergy, 2014;44:642–672
  10. National Institute of Health Care and Excellence Clinical Knowledge Summarises. Cows’ milk protein allergy in children, 2015 http://cks.nice.org.uk/cows-milk-protein-allergy-in-children#!diagnosissub/-617759 (Accessed October 2016)
  11. Vandenplas Y., et al. Acta Paed. 2015;104:334–39

IMPORTANT NOTICE: Mothers should be encouraged to continue breastfeeding even when their babies have cows' milk protein allergy. This usually requires qualified dietary counselling to completely exclude all sources of cows' milk protein from the mothers’ diet. If a decision to use a special formula intended for infants is taken, it is important to follow the instructions on the label. Unboiled water, unboiled bottles or incorrect dilution can make babies ill. Incorrect storage, handling, preparation and feeding can eventually lead to adverse effects on the health of babies. Formula for special medical purposes intended for infants must be used under medical supervision.