Differential Diagnosis for Non-Pruritic Full Body Rash
- Single Most Likely Diagnosis + Contact Dermatitis: This is the most likely diagnosis given the temporal relationship between using the TreeHut brand scrub and the onset of the rash. The fact that the rash started on the abdomen and spread to other areas suggests an allergic reaction to an ingredient in the scrub.
- Other Likely Diagnoses + Irritant Dermatitis: Similar to contact dermatitis, but caused by a non-allergic, direct irritation of the skin by the scrub. + Drug Rash (due to Benadryl): Although Benadryl is often used to treat allergic reactions, it can also cause a rash in some individuals, especially when used topically and orally. + Viral Exanthem: A viral infection could cause a rash that starts on the abdomen and spreads to other areas, although the temporal relationship with the scrub use makes this less likely.
- Do Not Miss Diagnoses + Stevens-Johnson Syndrome (SJS) or Toxic Epidermal Necrolysis (TEN): These are life-threatening conditions that can be caused by a severe allergic reaction to a medication or product. Although rare, they can present with a rash and require immediate medical attention. + Erythema Multiforme: A skin condition that can be triggered by infections or medications, characterized by a distinctive "target lesion" rash.
- Rare Diagnoses + Pityriasis Rubra Pilaris: A rare skin disorder characterized by a rash that starts on the face and spreads to other areas, often accompanied by palmoplantar keratoderma. + Cutaneous T-Cell Lymphoma: A type of skin cancer that can present with a rash, although this would be an unusual initial presentation. + Autoimmune Disorders (e.g. Lupus, Dermatomyositis): These conditions can cause a rash, but would typically be accompanied by other systemic symptoms and laboratory abnormalities.