The penis advice columnDear Marilyn:

I have read that the foreskin produces anti-microbial agents, including Langerhans cells. Is that true? What are Langerhans cells?

—Richard in Virginia

Dear Richard:

Yes, Richard, Langerhans cells have important immunological properties.

Langerhans cells reside in the epidermis of the foreskin, the body’s outermost and thinnest layer of skin and the layer responsible for protecting you from the outside world. Langerhans cells determine the appropriate adaptive immune response (inflammation or tolerance) by interpreting the microenvironmental context in which they encounter foreign substances. In a normal physiological, “non-dangerous” situation, Langerhans cells coordinate a continuous state of immune tolerance, preventing unnecessary and harmful immune activation. But when they sense a danger signal, for example during infection or when the physical integrity of skin has been compromised as a result of a trauma, they instruct T lymphocytes of the adaptive immune system to mount efficient responses against the danger.

Thus, Langerhans cells in the foreskin play an important role in fighting infections and protecting the rest of the penis.

—Marilyn Milos, RN