A 27-year-old man presents to his primary care physician for a checkup. He has no health concerns and has not seen a physician in years. The patient has a medical history of depression treated with fluoxetine and lithium. His temperature is 99.5°F (37.5°C), blood pressure is 122/78 mmHg, pulse is 90/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for the finding in Figure A. Which of the following represents the most likely risk factor for this patient's presenting condition?
Alcohol consumption
Antibiotic use
Intravenous drug use
Sexual intercourse
Alcohol consumption
This patient is presenting with adherent white plaques on the inside of the cheek consistent with oral leukoplakia. Alcohol consumption is a risk factor for this disease.

Oral leukoplakia presents with a white patch/plaque that occurs over the oral mucosa that is adherent and non-scrapable. Risk factors for this condition include the risk factors for squamous cell carcinoma such as consumption of alcohol and smoking. Though the cause of this lesion is largely idiopathic, any irritating substance can induce it. Other potential risk factors include candidiasis, vitamin deficiency, endocrine disturbances, and viral infections. A diagnosis can be made using a biopsy showing the degree of dysplasia. Treatment is with smoking and alcohol cessation as well as surgical removal for suspicious lesions.

Mohammed and Fairozekhan review the evidence regarding the diagnosis and risk factors for leukoplakia. They discuss how this disease is associated with smoking and alcohol use. They recommend screening patients for these modifiable risk factors.

Figure/Illustration A is a clinical photograph demonstrating adherent white plaques on the inside of the cheek (red circle). These findings are consistent with oral leukoplakia.

Incorrect Answers:
Answer B: Antibiotic use is a risk factor for candidiasis; however, this patient is not presenting with symptoms of candidiasis which is itself a risk factor for oral leukoplakia. Candidiasis presents with opaque white lesions that can be scraped off.

Answer C: Intravenous drug use does make this patient riskier overall for many conditions; however, alcohol is a more direct risk factor for oral leukoplakia. Immunodeficiency conditions can cause widespread fungal and viral infections on the mucosal surfaces.

Answer D: Poor dental hygiene may be found more often in patients with oral leukoplakia; however, it is not itself a direct cause.

Answer E: Sexual intercourse would predispose this patient to infections and viruses (such as Epstein-Barr virus); however, it is a less likely risk factor than is alcohol consumption or smoking. These infections tend to present with ulcers more commonly than leukoplakia.

Bullet Summary:
Risk factors for oral leukoplakia and squamous cell carcinoma include alcohol consumption and smoking.