Fordyce disease most commonly involves
**Core Concept**
Fordyce disease, also known as Fordyce granules or Fordyce spots, is a benign condition characterized by the presence of ectopic sebaceous glands on the mucosal surfaces of the oral cavity, including the lips, cheeks, and genitalia.
**Why the Correct Answer is Right**
The condition results from the abnormal development of sebaceous glands, which are usually found in the skin. In Fordyce disease, these glands become ectopic, meaning they are located in an unusual or abnormal position. The sebaceous glands in the oral cavity produce sebum, which can cause small, painless bumps or spots to appear on the mucosal surfaces. The correct answer is related to the mucosal surfaces involved in Fordyce disease.
**Why Each Wrong Option is Incorrect**
**Option A:** The tongue is not a common location for Fordyce granules.
**Option B:** The skin is the typical location for sebaceous glands, not the mucosal surfaces of the oral cavity.
**Option C:** The conjunctiva is not a common location for Fordyce granules.
**Clinical Pearl / High-Yield Fact**
Fordyce granules are usually harmless and do not require treatment, but they can be a source of concern for patients who are concerned about their appearance.
**Correct Answer: D. Oral mucosal surfaces.**