Differential Diagnosis for a Penile Linear Sore
Single Most Likely Diagnosis
- Herpes Simplex Virus (HSV) Infection: This is often the first consideration for a penile linear sore due to its prevalence and the characteristic presentation of painful, linear, or clustered vesicles or ulcers.
Other Likely Diagnoses
- Syphilis (Primary): The primary stage of syphilis can present with a single, painless chancre, which can sometimes appear linear, especially if it follows the path of a scratch or other minor trauma.
- Genital Herpes Zoster (Shingles): This condition can cause a linear distribution of painful vesicles or ulcers, typically confined to one side of the penis and associated with a dermatomal distribution.
- Traumatic or Irritative Lesions: Linear sores can result from direct trauma, irritation from clothing, or other external factors, which might cause friction or chemical burns.
Do Not Miss Diagnoses
- Squamous Cell Carcinoma: Although rare, any persistent or non-healing sore should raise concern for malignancy, such as squamous cell carcinoma, which can present as a linear or irregular ulcer.
- Lymphogranuloma Venereum (LGV): This sexually transmitted infection can cause ulcerative lesions, although they are less commonly linear and often accompanied by lymphadenopathy.
Rare Diagnoses
- Behçet's Disease: A form of vasculitis that can cause genital ulcers, which might appear linear, along with oral ulcers and other systemic symptoms.
- Fixed Drug Eruption: A condition that can cause well-defined, sometimes linear, lesions in response to certain medications, which typically recur at the same site upon re-exposure to the offending drug.
- Granuloma Inguinale (Donovanosis): A sexually transmitted infection that can cause ulcerative lesions, which are typically beefy-red, painless, and can have a linear or irregular shape.