The ABO and Rh systems are the most commonly used blood‐group systems used to classify blood group globally. A number of studies have shown that ABO blood groups may be associated with an increased serum cholesterol levels which in turn may be related to the presence of oral Fordyce spots or granules. Oral Fordyce's granules are ectopic sebaceous glands within the oral cavity and are visible through epithelium. The aim of this study was to assess the relationship between ABO and Rhesus blood groups and the presence of oral Fordyce's granules and serum cholesterols level by gender.

Following ethical approval and informed consent, 124 subjects were recruited into this cross‐sectional study. Clinical oral examination assessed the number of Fordyce's granules and blood samples were collected to determine the serum cholesterol and ABO/Rh blood‐group systems of individual subjects.

Blood group AB⁺ showed the highest mean of oral Fordyce's granules number and serum cholesterol level but this was not statistically significant compared to other blood groups. Female subjects in this study who were AB⁺ were had significantly higher serum cholesterol levels than males.

This study indicates an association between ABO blood group, serum cholesterol level and mean number of oral Fordyce's granules. A larger sample size in a future study is required to ascertain whether number of Fordyce's granules is an important measure of serum cholesterol, but the study does show that for AB⁺ individuals, females may have higher serum cholesterol than males.