Differential Diagnosis for Dry Itchy Patches Under Arms in Adults
Single Most Likely Diagnosis
- Contact Dermatitis: This is the most likely diagnosis, as dry itchy patches under the arms can be caused by irritation from deodorants, antiperspirants, or other personal care products. The warm and moist environment under the arms can exacerbate the irritation.
Other Likely Diagnoses
- Eczema (Atopic Dermatitis): Eczema can cause dry, itchy patches on the skin, including under the arms. Adults with a history of eczema or allergies are more likely to experience this condition.
- Seborrheic Dermatitis: This condition causes a red, itchy rash, often in oily areas of the body, including under the arms. It can be triggered by stress, hormones, or certain medical conditions.
- Fungal Infections (Intertrigo): Fungal infections can thrive in warm, moist areas like under the arms, causing dry, itchy patches. Obesity, diabetes, and poor hygiene can increase the risk of developing intertrigo.
Do Not Miss Diagnoses
- Lymphoma: Although rare, lymphoma can cause itchy skin, including under the arms. It's essential to consider this diagnosis, especially if the patient has other symptoms like weight loss, fever, or night sweats.
- Hodgkin's Disease: This type of lymphoma can cause itchy skin, particularly under the arms, as well as other symptoms like fatigue, weight loss, and swollen lymph nodes.
Rare Diagnoses
- Pityriasis Rosea: This rare skin condition causes a rash, often with dry, itchy patches, which can appear under the arms. It's usually triggered by a viral infection and resolves on its own.
- Psoriasis: Although psoriasis typically affects other areas of the body, it can occasionally cause dry, itchy patches under the arms. This diagnosis is less likely but should be considered if other symptoms like joint pain or nail changes are present.