Differential Diagnosis for Pruritic Rash
- Single most likely diagnosis
- Atopic dermatitis (eczema): This is a common condition characterized by itchy, inflamed skin, and is often the first consideration for a pruritic rash, especially in children and individuals with a history of allergies or asthma.
- Other Likely diagnoses
- Contact dermatitis: This condition occurs when the skin comes into contact with an allergen or irritant, leading to a pruritic rash. It's common and can be caused by a wide range of substances.
- Psoriasis: An autoimmune condition that speeds up the life cycle of skin cells, causing cells to build up rapidly on the surface of the skin. The extra skin cells form scales and red patches that itch or burn.
- Urticaria (hives): Characterized by itchy, raised welts on the skin, often caused by an allergic reaction.
- Insect bites or stings: Can cause pruritic rashes, especially in individuals allergic to the venom.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Meningococcemia: A severe infection that can cause a rash, which may initially be pruritic, but quickly progresses to a more severe, life-threatening condition.
- Erythema multiforme: A skin condition characterized by target lesions, which can be itchy, and is often associated with infections or medications.
- Stevens-Johnson syndrome: A rare but serious disorder of the skin and mucous membranes, usually caused by an adverse reaction to medication or infection.
- Rare diagnoses
- Pemphigus: A group of rare skin disorders that cause blistering of the skin and mucous membranes, which can be itchy.
- Dermatitis herpetiformis: A chronic skin condition characterized by blisters filled with a watery fluid, which can be itchy, and is associated with celiac disease.
- Cutaneous T-cell lymphoma (Mycosis fungoides): A rare type of cancer that initially presents as a pruritic rash, which can mimic more common skin conditions.