Differential Diagnosis for a Painful White Pimple on the Penis
- Single most likely diagnosis:
- Folliculitis: This is an inflammation of the hair follicles, which can cause white, painful pimples. It's common in areas with hair, including the genital region, and can be caused by bacterial or fungal infections.
- Other Likely diagnoses:
- Ingrown Hair (Pseudofolliculitis): This occurs when hair curls back into the skin, causing inflammation, which can lead to painful, white bumps.
- Herpes Simplex Virus (HSV): Although typically associated with vesicles or blisters, in some cases, especially during the initial outbreak, lesions can appear as painful, white pimples.
- Syphilis (Primary): The primary stage of syphilis can present with a single, painless chancre, but in some cases, it might be painful and could be mistaken for a pimple.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Methicillin-Resistant Staphylococcus aureus (MRSA): Although less common, MRSA infections can cause skin lesions that resemble pimples but are more serious and require specific treatment.
- Genital Warts: Caused by the Human Papillomavirus (HPV), these can sometimes appear as small, white bumps and are important to diagnose due to their association with cervical cancer and other health issues.
- Rare diagnoses:
- Molluscum Contagiosum: A viral infection that causes small, pearly, or flesh-colored bumps. It's contagious and can appear anywhere on the body, including the genital area.
- Keratoacanthoma: A rare, low-grade malignancy that can resemble a large pimple but is typically found on sun-exposed areas. Its appearance in the genital area would be extremely rare.