My attention was called to the possibility of congenital epidermal canals being responsible for chronic inflammation of the perineal raphe by the following case.
REPORT OF A CASE
An American of Bohemian ancestry, aged 23, was first seen on Feb. 7, 1939. He complained of several small but painful ulcers distributed along the under surface of the penis and the midline of the scrotum. He related that while working in the wheat harvest in the late summer of 1937 he noticed a small reddened lesion on the posterior aspect of the penis 2 or 3 inches (5 to 7.5 cm.) from the prepuce. He consulted a dermatologist, to whom the appearance suggested larva migrans and who prescribed calamine lotion for local application, but in a few months a new lesion appeared at the penoscrotal junction.The patient consulted another physician, who made a diagnosis of local venereal infection (probably chancroid)
LAMB OH. CONGENITAL EPIDERMAL CANALS OF THE PERINEAL RAPHE. Arch Derm Syphilol. 1943;47(1):74–81. doi:10.1001/archderm.1943.01500190077008