**Core Concept**
Condoms are a popular form of contraception and STI prevention. However, their use can be associated with various adverse effects, particularly skin-related issues due to the materials used in their manufacturing process.

**Why the Correct Answer is Right**
Contact dermatitis is a common skin reaction that occurs when the skin comes into contact with an allergen or irritant. Condoms, especially those made from latex, can cause contact dermatitis in some individuals. This is because latex contains proteins such as Hev b 1 and Hev b 3, which can trigger an allergic response. Furthermore, the chemicals used in the manufacturing process, such as accelerators and vulcanizers, can also cause skin irritation. The symptoms of contact dermatitis associated with condom use can range from mild redness and itching to more severe blistering and open sores.

**Why Each Wrong Option is Incorrect**
**Option A:** Increased monilial infection of vagina is not directly related to condom use. While condoms can reduce the risk of STIs, they do not increase the risk of vaginal infections such as monilial (yeast) infections.

**Option B:** Premature ejaculation is not a common problem associated with condom use. In fact, condoms can help men last longer during sex by providing a physical barrier that reduces sensitivity.

**Option D:** Retention of urine is not a known side effect of condom use. Condoms do not affect bladder function or the ability to urinate.

**Clinical Pearl / High-Yield Fact**
When using condoms, it's essential to choose a condom that is hypoallergenic and made from a material that is less likely to cause skin irritation, such as polyurethane or polyisoprene. Additionally, users should follow proper storage and handling techniques to minimize the risk of skin reactions.

**✓ Correct Answer: C. Contact dermatitis**