Differential Diagnosis for Swollen Penis Shaft in Children

Single Most Likely Diagnosis

• Trauma: This is the most common cause of a swollen penis shaft in children, often resulting from accidental injury, such as a blow to the penis or from vigorous sexual play.

Other Likely Diagnoses

• Balanitis: An inflammation of the glans penis, which can extend to the shaft, often caused by poor hygiene, infection, or an allergic reaction.
• Phimosis: A condition where the foreskin cannot be fully retracted over the glans, which can lead to swelling and inflammation of the penis shaft due to trapped secretions and bacteria.
• Urethritis: Inflammation of the urethra, which can cause swelling and pain in the penis shaft, often due to infection.

Do Not Miss Diagnoses

• Paraphimosis: A condition where the foreskin is retracted behind the glans and cannot return to its original position, leading to swelling and potential ischemia of the penis. This is a medical emergency.
• Testicular torsion: Although it primarily affects the testicles, severe cases can lead to swelling that might be perceived as involving the penis shaft. It's a surgical emergency.
• Epispadias: A rare congenital condition where the urethra opens on the upper aspect of the penis, which can lead to swelling and other complications if not properly managed.

Rare Diagnoses

• Henoch-Schönlein Purpura (HSP): A systemic vasculitis that can cause skin lesions, joint pain, and abdominal pain, and in rare cases, genital swelling, including the penis shaft.
• Fabry Disease: A genetic disorder that can lead to the accumulation of a particular type of fat in the body's cells, affecting many parts of the body, including causing pain and swelling in the genital area.
• Sarcoidosis: A condition where inflammatory cells form lumps known as granulomas in various parts of the body, which can rarely affect the genital area, including the penis.