Differential Diagnosis for Rash All Over Body
Single Most Likely Diagnosis
- Viral Exanthem: This is often the most common cause of a rash all over the body, especially in children and young adults. Viral exanthems are associated with a variety of viruses and can present with a wide range of rash characteristics, from maculopapular to vesicular.
Other Likely Diagnoses
- Allergic Reaction: An allergic reaction to medications, foods, or environmental factors can cause a widespread rash. This could range from a mild, itchy rash to a severe, life-threatening reaction like Stevens-Johnson syndrome.
- Eczema (Atopic Dermatitis): A chronic condition characterized by dry, itchy skin, and is often seen in individuals with a history of allergies or asthma. It can flare up and spread across the body.
- 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 are itchy and sometimes painful.
Do Not Miss Diagnoses
- Toxic Epidermal Necrolysis (TEN): A severe skin condition usually triggered by medications, leading to widespread skin necrosis and detachment. It's a medical emergency with a high mortality rate if not promptly treated.
- Stevens-Johnson Syndrome: A rare but serious disorder of the skin and mucous membranes, usually a reaction to medication or infection. It's characterized by a painful rash that can lead to blisters and peeling of the skin.
- Meningococcemia: A severe infection caused by Neisseria meningitidis, which can present with a rash (petechiae or purpura) and is a medical emergency due to the risk of sepsis and meningitis.
Rare Diagnoses
- Pityriasis Rubra Pilaris: A rare skin disorder characterized by salmon-colored patches and thickening of the skin, often accompanied by palmoplantar keratoderma.
- Kawasaki Disease: An acute febrile illness of childhood characterized by inflammation in the walls of medium-sized arteries throughout the body, which can include a rash among its symptoms.
- Erythema Multiforme: A skin condition characterized by target lesions, often triggered by infections or medications. While not typically life-threatening, it can be a sign of a significant underlying issue.