Differential Diagnosis for Prickly Rash

• Single most likely diagnosis
  • Keratosis pilaris: This condition is characterized by small, rough, sandpaper-like bumps on the skin, often accompanied by a prickly sensation. It's a common condition, especially in children and adolescents, and typically appears on the arms, legs, buttocks, and cheeks.
• Other Likely diagnoses
  • Eczema (atopic dermatitis): A chronic skin condition that can cause dry, itchy, and prickly skin. It often appears as red, inflamed patches on the skin.
  • Contact dermatitis: A type of skin inflammation caused by contact with irritants or allergens, leading to a prickly rash, redness, and itching.
  • Urticaria (hives): Although typically itchy, some cases of hives can feel prickly, especially if they are chronic or caused by certain allergens.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Sepsis or systemic infection: In rare cases, a prickly rash can be a sign of a life-threatening infection, such as sepsis or meningitis, especially if accompanied by fever, confusion, or severe pain.
  • Meningococcemia: A severe infection caused by Neisseria meningitidis, which can cause a rash that may initially feel prickly before progressing to purpura (bleeding into the skin).
• Rare diagnoses
  • Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet, which can sometimes be described as a prickly sensation.
  • Cutaneous lymphoma: Certain types of skin lymphoma can cause a prickly rash, although this is extremely rare and usually accompanied by other symptoms such as weight loss or lymphadenopathy.