Differential Diagnosis for Itchy Rash in a 6-Year-Old
Single Most Likely Diagnosis
- Atopic Dermatitis (Eczema): This is the most common skin condition in children, characterized by itchy, inflamed skin. It often starts in infancy but can persist into childhood, making it a likely diagnosis for a 6-year-old with an itchy rash.
Other Likely Diagnoses
- Contact Dermatitis: This condition occurs when the skin comes into contact with an allergen or irritant, leading to an itchy rash. Common culprits include poison ivy, oak, or sumac, as well as certain metals or chemicals in soaps or lotions.
- Insect Bites or Stings: Mosquito bites, flea bites, or other insect bites can cause itchy rashes in children.
- Scabies: A contagious skin infestation caused by the mite Sarcoptes scabiei, leading to intense itching and a pimple-like rash.
- Keratosis Pilaris: A harmless condition that causes small, rough patches on the skin, often accompanied by itching.
Do Not Miss Diagnoses
- Meningococcemia: Although rare, this condition can present with a rash and is life-threatening if not promptly treated. The rash associated with meningococcemia is typically non-itchy, but it's crucial to consider this diagnosis in any child with a new rash.
- Stevens-Johnson Syndrome: A severe skin and mucous membrane disorder, usually a reaction to medication or infection. It's characterized by a painful rash, but the initial stages might include itching.
- Henoch-Schönlein Purpura (HSP): A form of vasculitis that affects blood vessels and is characterized by a purpuric rash, which might be itchy. HSP can also involve the kidneys, joints, and gastrointestinal tract.
Rare Diagnoses
- Pityriasis Rosea: A skin condition characterized by a rash that starts with a single, large spot (herald patch) followed by an eruption of smaller spots, often itchy.
- Pityriasis Alba: A mild form of atopic dermatitis that presents as small, round, faint patches on the face, often accompanied by mild itching.
- Lichen Striatus: A rare, self-limiting condition that causes a blistering rash, usually on one arm or leg, which can be itchy.
- Dyshidrotic Eczema: A type of eczema that primarily affects the hands and feet, characterized by small, itchy blisters.