Differential Diagnosis for Itchy Rash

• Single most likely diagnosis
  • Atopic dermatitis (eczema): This is a common condition characterized by itchy, inflamed skin. It's often seen in individuals with a history of allergies or asthma, and the itch can be severe enough to disrupt daily activities.
• Other Likely diagnoses
  • Contact dermatitis: This condition occurs when the skin comes into contact with an allergen or irritant, leading to an itchy rash. It can be acute or chronic, depending on the duration of exposure.
  • 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.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Bullous pemphigoid: A rare autoimmune disease that causes blistering of the skin and can be life-threatening if not treated promptly.
  • Erythema multiforme: A skin condition characterized by target-shaped lesions, which can be a sign of a severe allergic reaction or infection.
  • Stevens-Johnson syndrome: A rare but serious disorder of the skin and mucous membranes, often caused by an adverse reaction to medication or infection.
• Rare diagnoses
  • Pemphigus vulgaris: A rare autoimmune disease that causes severe blistering of the skin and mucous membranes.
  • Dermatitis herpetiformis: A chronic skin condition characterized by blisters filled with a watery fluid, often associated with celiac disease.
  • Cutaneous T-cell lymphoma (mycosis fungoides): A rare type of cancer that affects the skin, causing lesions, patches, or tumors that can be itchy.