**Core Concept**
Chlorhexidine is a widely used antiseptic and disinfectant, particularly in healthcare settings for skin preparation and oral care. Its long-term use can have significant effects on the skin and mucous membranes.

**Why the Correct Answer is Right**
Chlorhexidine's primary mechanism of action is binding to the bacterial cell wall, ultimately leading to cell death. However, its long-term use can cause skin irritation, allergic contact dermatitis, and even mucous membrane damage. This is due to the accumulation of chlorhexidine's metabolites, which can lead to a local increase in pH, disrupting the natural skin flora and causing irritation. The skin's natural barrier function can be compromised, making it more susceptible to infections and other complications.

**Why Each Wrong Option is Incorrect**
* **Option A:** Chlorhexidine's long-term use does not typically cause systemic toxicity or organ damage, as it is primarily excreted in the urine without significant metabolism.
* **Option B:** While chlorhexidine can be associated with oral mucositis, this is not the most accurate description of its long-term effects.
* **Option C:** Chlorhexidine's use is not commonly linked to the development of antibiotic resistance in bacteria.

**Clinical Pearl / High-Yield Fact**
It is essential to use chlorhexidine judiciously and follow recommended guidelines for its use, especially in patients with sensitive skin or mucous membranes. A concentration of 0.5% is generally considered safe for long-term use, and the duration of application should be limited to minimize the risk of irritation.

**Correct Answer: B. Oral mucositis and mucous membrane damage can occur with long-term use of chlorhexidine.**