Children get rash often due to infections, worm infestations, irritants, environmental factors and even when they are emotional. If due to food allergy they could be either limited to around mouth - Oral allergy syndrome or involve the whole body. Having a food diary might be helpful if you strongly suspect food allergy. Tests are available to confirm if there is a strong history.

Seek advice, if:

1. • Rash appears immediately after ingestion of a particular food
   

2. • Rash appeared at least more then once after ingestion
   

3. • Had severe reaction ( swelling of tongue, difficulty in breathing or collapse)
   

4. • Had the reaction recently
   

Read further:

1. 1. NHS Choice
   

2. 2. Allergy UK