Differential Diagnosis for Penile Itching after Oral Sex
- Single Most Likely Diagnosis
- Genital herpes: This is a common sexually transmitted infection (STI) that can cause itching, burning, and painful blisters or sores on the genitals, including the penis. The symptoms can appear after oral sex if the partner has oral herpes, which can be transmitted to the genitals.
- Other Likely Diagnoses
- Gonorrhea: This STI can cause itching, burning, and discharge from the penis. It can be transmitted through oral sex if the partner has gonorrhea in their throat.
- Chlamydia: Similar to gonorrhea, chlamydia is an STI that can cause penile discharge, itching, and burning. It can also be transmitted through oral sex.
- Syphilis: The primary stage of syphilis can cause a painless sore or ulcer on the penis, which may be accompanied by itching. Syphilis can be transmitted through oral sex.
- Phthirus pubis (crab lice): These parasites can cause intense itching in the genital area and can be transmitted through close contact, including oral sex.
- Do Not Miss Diagnoses
- HIV: Although less likely to cause immediate symptoms like itching after oral sex, HIV is a critical diagnosis not to miss due to its long-term implications and the importance of early treatment. Oral sex can transmit HIV if the partner is infected and has open sores or bleeding gums.
- Primary syphilis with systemic symptoms: While syphilis is listed as an "other likely diagnosis," it's crucial to recognize that if left untreated, syphilis can progress to more severe stages, affecting various body systems.
- Rare Diagnoses
- Scabies: Caused by the mite Sarcoptes scabiei, scabies can lead to severe itching and is typically spread through direct, prolonged skin-to-skin contact. It's less common for scabies to be transmitted through oral sex but not impossible.
- Contact dermatitis: An allergic reaction or irritation from certain substances (like spermicides, lubricants, or even components of a partner's saliva) could potentially cause itching, though this would be less common and typically not as severe as the other conditions listed.