Differential Diagnosis for Redness and Sensitivity on Arms
Single most likely diagnosis
- Contact Dermatitis: This is a common condition that occurs when the skin comes into contact with an irritant or allergen, leading to redness, sensitivity, and sometimes a rash. The intermittent nature of the symptoms and their localization to the arms suggest a possible allergic or irritant reaction to something that comes into contact with the skin, such as soaps, detergents, or plants.
Other Likely diagnoses
- Eczema (Atopic Dermatitis): A chronic condition characterized by dry, itchy, and inflamed skin. It can cause redness and sensitivity, especially if the skin is exposed to triggers or irritants.
- Keratosis Pilaris: A harmless condition that causes small, rough patches on the skin, often on the arms, which can sometimes appear red and feel sensitive due to dryness.
- Heat Rash (Miliaria): Caused by blocked sweat ducts, leading to redness, itching, and small bumps, especially in warm weather or after intense exercise.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cellulitis: A bacterial skin infection that can cause redness, swelling, and sensitivity. It requires prompt antibiotic treatment to prevent serious complications.
- Lupus: An autoimmune disease that can cause skin rashes, including a butterfly-shaped rash on the face, but can also affect other areas like the arms, along with systemic symptoms.
- Vasculitis: Inflammation of the blood vessels, which can cause a variety of skin symptoms including redness, sensitivity, and rashes, and can be associated with serious systemic disease.
Rare diagnoses
- Erythema Multiforme: A skin condition characterized by target-shaped lesions, which can be triggered by infections or medications. It's rare but can be serious.
- Cutaneous T-Cell Lymphoma (Mycosis Fungoides): A rare type of skin cancer that can cause patches of red, scaly skin, which may resemble eczema or dermatitis but does not respond to usual treatments.
- Sarcoidosis: A condition where inflammatory cells form lumps known as granulomas in various parts of the body, including the skin, which can cause red, sensitive lesions.