Are allergic diseases common in preschool-aged children (3–5 years)?

Are Allergies Common in 3-5 Year Old Children?

Yes, allergic diseases are highly prevalent in preschool-aged children (3-5 years), affecting a substantial proportion of this population and representing a significant public health concern.

Prevalence of Allergic Diseases in Preschool Children

Food Allergies

• Food allergy affects approximately 8% of all children, making it a rapidly emerging public health issue 1
• The prevalence increased by 18% over the decade preceding 2007, with parallel rises in ambulatory care visits and food allergy-related hospitalizations 1
• Up to 37% of children younger than 5 years with moderate-to-severe atopic dermatitis have IgE-mediated food allergy 2
• The 8 most common pediatric food allergens are peanut, tree nut, cow's milk, shellfish, fin fish, egg, wheat, and soy 1
• Approximately 30.4% of children with food allergy have multiple food allergies 1

Atopic Dermatitis (Eczema)

• The prevalence of atopic dermatitis symptoms in the last 12 months ranges from 18.1% to 21.7% in preschool children 3, 4, 5
• Doctor-diagnosed eczema prevalence is approximately 15.4% to 35.1% (lifetime diagnosis) in this age group 3, 6, 5
• 72% of children with atopic dermatitis present with AD-specific localizations 5

Allergic Rhinitis

• Allergic rhinitis is remarkably common, with prevalence ranging from 8.1% to 40.7% in preschool children 7, 3, 4
• Epidemiologic criteria may overestimate prevalence at 48%, but when confirmed with skin prick testing, the adjusted clinical prevalence is 14.9% 7
• Urban areas show higher prevalence (19.5%) compared to suburban areas (10.8%), suggesting environmental risk factors play an important role 7
• Rhinitis prevalence increases consistently with age through the preschool years, unlike other allergic conditions 4

Asthma

• The prevalence of asthma symptoms in preschool children is approximately 8.7% to 13.8% 3, 6, 4
• Current treatment rates are lower at 4.4%, indicating potential underdiagnosis or undertreatment 6

Other Allergic Manifestations

• Allergic conjunctivitis affects approximately 14.8% of preschool children 3
• Drug allergy is relatively rare at 0.8% 3

Co-occurrence and Comorbidities

Children with one allergic disease are 2 to 4 times more likely to have related conditions, demonstrating the interconnected nature of allergic diseases 2:

• Children with food allergy have 4-fold increased odds of asthma 2, 1, 2
• Children with food allergy have 2.4-fold increased odds of atopic dermatitis 2
• Children with food allergy have 3.6-fold increased odds of respiratory allergies 2
• 35.7% of preschool children have at least one atopic manifestation 4
• The prevalence of allergic rhinitis in children with asthma is 64.3%, while the prevalence of asthma in children with allergic rhinitis is 21.6% 3
• Allergic conjunctivitis shows close association with both asthma and allergic rhinitis, with 64.8% of children with conjunctivitis also having rhinitis 3

Age-Related Patterns

The prevalence of most allergic manifestations follows a curvilinear pattern in preschool years 4:

• Asthma, eczema, and food allergy prevalence increases from age 1 to 3 years, then decreases 4
• Rhinitis prevalence increases consistently from ages 1 to 6 years, showing no decline 4
• This pattern indicates no specific ordered sequence of allergic disease onset, contrary to the traditional "allergic march" concept 4

Clinical Implications

High-Risk Groups

Children with severe eczema within the first 6 months of life have significantly increased risk of developing peanut, milk, and egg allergy 1

Atopic Sensitization

• Positive atopic sensitization is present in 18.6% of the total preschool population and 32.2% of children with atopic dermatitis 5
• Multiple sensitivities occur in 58.2% of sensitized children 5
• The most common sensitizing allergens are dust mites and grass pollen 5

Impact on Quality of Life

Allergic diseases in preschoolers are associated with psychological and behavioral problems 6:

• Internalizing and sleep problems are significantly higher in children diagnosed with allergic rhinitis 6
• Children treated for atopic dermatitis have higher attention problem scores 6
• Sleep problems correlate positively with eosinophil percentage in peripheral blood 6

Important Caveats

• Self-reported food allergy prevalence (12-13%) is significantly higher than confirmed food allergy (3%) when assessed by symptoms plus sensitization or double-blind food challenge 2
• Positive skin prick tests or specific IgE blood tests indicate sensitization but do not alone confirm clinical allergy—93% of children avoiding foods based solely on positive tests were actually tolerant when challenged 8
• Epidemiologic criteria without confirmatory testing can overestimate allergic rhinitis prevalence by more than 3-fold 7