Differential Diagnosis for Rash
- Single most likely diagnosis
- Eczema (Atopic Dermatitis): This is often the most common cause of rash, especially in children and individuals with a history of allergies. It presents with itchy, inflamed skin that can appear anywhere on the body.
- Other Likely diagnoses
- Contact Dermatitis: This occurs when the skin comes into contact with an irritant or allergen, leading to a rash. It's common and can be caused by a variety of substances, including soaps, metals, and plants.
- 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.
- Allergic Reaction: Can be caused by a wide range of allergens, including foods, medications, and insect bites. Symptoms can range from mild to severe and include hives, itching, and swelling.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningococcemia: A severe infection caused by the bacterium Neisseria meningitidis. It can cause a rash that is often accompanied by fever, headache, and stiff neck. Early recognition and treatment are crucial as it can be fatal if not promptly addressed.
- Rocky Mountain Spotted Fever (RMSF): A bacterial infection transmitted by ticks. It causes fever, headache, and a characteristic rash. If not treated promptly, it can be fatal.
- Toxic Epidermal Necrolysis (TEN) and Stevens-Johnson Syndrome (SJS): These are severe skin conditions usually triggered by medications. They cause widespread skin necrosis and detachment, and are medical emergencies.
- Rare diagnoses
- Pemphigus: A group of rare skin disorders that cause blistering of the skin and mucous membranes. It's an autoimmune disease that can be life-threatening if not treated.
- Kawasaki Disease: An illness that affects children and causes inflammation in the walls of medium-sized arteries throughout the body. It's characterized by fever, rash, swelling of the hands and feet, and other symptoms.
- Erythema Multiforme: A skin condition characterized by target lesions. It can be triggered by infections or medications and, while usually self-limiting, can be a sign of a more serious condition in some cases.