Allergy care pathway for urticaria, angio-odema or mastocytosis

Urticaria is characterised by fluctuating swellings and/or angio-oedema. Angio-odema is a sudden, central swelling of variable size that can be painful rather than itchy. Mastocytosis is the abnormal growth and accumulation of mast cells (MC). This is one of several allergy care pathways, which tell health professionals what they need to know in order to provide the best care possible.


The College's care pathway for urticaria, angio-oedema or mastocytosis (UAM) is presented in two parts:

  • an algorithm with the stages of ideal care, and
  • a set of competences required to diagnose, treat and optimally manage UAM.

The algorithm has numbers which correspond to the competences outlined within the body of the document.

We recommend that this pathway is implemented locally by a multidisciplinary team with a focus on creating networks between staff in primary and community healthcare, social care, education and hospital-based practice to improve services for children with allergic conditions. All specialists should have paediatric training.

Download the full RCPCH Care Pathway for Children with Urticaria, Angio-oedema or Mastocytosis below.



Chronic urticaria is relatively common with up to 3% of children being affected. Acute urticaria occurs more commonly with between 4.5-15% of UK children. Urticaria is characterised by fluctuating weals and/or angio-oedema. A weal consists of three typical features:

  • a central swelling of variable size, almost invariably surrounded by a reflex erythema
  • associated itching or, sometimes, burning sensation
  • a fleeting nature, with the skin returning to its normal appearance, usually within 1 - 24 hours.

Chronic urticaria is characterised by continuous symptoms that persist for more than six weeks.

Episodic urticaria is characterised by the occurrence of repeated relapses of urticaria with intervals of at least a week between each relapse. Urticarial vasculitis is distinguished by palpable purpura and bruising or discoloration that persists after the weal has disappeared. The urticarial lesions persist for more than 24 hours and respond poorly to antihistamines. The most common cause in childhood is Henoch-Schönlein purpura.


Angio-oedema is characterised by:

  • a sudden, pronounced swelling of the lower dermis and subcutis, which is pale rather than pink and may be painful rather than itching
  • frequent involvement below mucous membranes
  • resolution that is slower than for weals and can take up to 72 hours.

Hereditary angio-oedema (HAE) is rare, with no reported bias in different ethnic groups. HAE has an estimated population prevalence of one in 50,000. In cases of HAE symptoms may also include abdominal pain due to intestinal oedema causing obstruction.


Mastocytosis is a heterogeneous group of disorders characterised by abnormal growth and accumulation of mast cells (MC) in one or more organ systems. Mastocytosis is uncommon; figures for prevalence are unknown.

The diagnosis of cutaneous mastocytosis (CM) in children is based on typical clinical and histological skin lesions and absence of systemic involvement. Most children present with maculopapular cutaneous mastocytosis (urticaria pigmentosa or UP). Other, less frequent forms of CM are diffuse cutaneous mastocytosis (DCM) and mastocytoma of skin.