Differential Diagnosis for Red Rash on Scrotum with Discharge

Single Most Likely Diagnosis

• Eczema/Dermatitis: This is a common condition that can cause a red rash and discharge on the scrotum, often due to allergic reactions or irritants. The worsening of symptoms could be due to continued exposure to the causative agent or secondary infection.

Other Likely Diagnoses

• Tinea Cruris (Jock Itch): A fungal infection that thrives in warm, moist areas of the body, such as the groin. It can cause a red, itchy rash and sometimes discharge if secondarily infected.
• Balanitis: An inflammation of the glans penis, which can extend to the scrotum, often caused by poor hygiene, infections (bacterial, fungal, or viral), or allergic reactions. It can present with redness, swelling, and discharge.
• Contact Dermatitis: Similar to eczema but specifically caused by contact with an allergen or irritant. This could be from soaps, laundry detergents, or other substances coming into contact with the scrotal skin.

Do Not Miss Diagnoses

• Sexually Transmitted Infections (STIs): Such as gonorrhea, chlamydia, or syphilis, which can cause discharge and rashes in the genital area. These conditions are critical to diagnose and treat promptly to prevent long-term complications and transmission to others.
• Cellulitis: A bacterial skin infection that can cause redness, swelling, and sometimes discharge. It requires antibiotic treatment and can be serious if not addressed.

Rare Diagnoses

• Lichen Sclerosus: A rare condition that creates patchy, white skin that's thinner than normal. It can cause itching, pain, and bleeding, and sometimes appears as a red rash if inflamed or secondarily infected.
• Keratosis Pilaris: A condition that causes small, rough patches on the skin, which can sometimes appear on the scrotum. While not typically associated with discharge, in rare cases, it could lead to secondary infections if the skin barrier is compromised.
• Zoon's Balanitis: A rare condition affecting the glans penis, characterized by a well-demarcated, red, erosive plaque. It's more common in uncircumcised men and could potentially extend to the scrotum, though this is less common.

Each of these diagnoses has distinct features, but the presentation can sometimes overlap, making a thorough medical history, physical examination, and possibly diagnostic tests necessary for an accurate diagnosis.