Contact Dermatitis: This is a common condition that can cause penile irritation due to allergic reactions or irritants such as soaps, condoms, or other products. The lack of UTI symptoms makes this a plausible first consideration.

Balanitis: An inflammation of the glans penis, often caused by poor hygiene, infections (bacterial, fungal, or viral), or irritants. It's a common condition in uncircumcised men and can present with irritation.
Phimosis: A condition where the foreskin cannot be fully retracted over the glans penis, which can lead to irritation, especially if there is an underlying infection or poor hygiene.
Sexually Transmitted Infections (STIs): Such as gonorrhea, chlamydia, or herpes simplex virus, which can cause penile irritation without the typical symptoms of a urinary tract infection.

Squamous Cell Carcinoma: Although rare, penile cancer can present with chronic irritation or a lesion on the penis. Early detection is crucial for effective treatment.
Lichen Sclerosus: A chronic inflammatory skin condition that can cause significant irritation and, if left untreated, can lead to scarring and increased risk of penile cancer.

Zoon's Balanitis: A rare condition characterized by a chronic, painless, erosive balanitis, typically affecting middle-aged to elderly uncircumcised men.
Fixed Drug Eruption: A condition where certain medications cause skin lesions, including on the penis, which can be mistaken for other forms of irritation or infection.
Psoriasis or Eczema: Although more commonly associated with other body parts, these conditions can occasionally cause penile irritation and should be considered in the differential diagnosis, especially in patients with a history of these conditions.