What is the cause of hypertrichosis lanuginosa acquisita?
The cause of hypertrichosis lanuginosa acquisita is unknown but it is thought to be in response to hormones or substances released by the tumour. Most cases of hypertrichosis lanuginosa acquisita are associated with an internal malignancy. The most frequently associated cancers include lung, breast and uterine cancers, colorectal cancer, lymphoma, and bladder cancer. The ‘malignant down’ most often occurs late in the course of the cancer, however in some cases it may be the presenting sign of a tumour and can appear up to 2 years prior to diagnosis of cancer. Less commonly, hypertrichosis lanuginosa acquisita is associated with non-malignant disease such as anorexia nervosa, hyperthyroidism, and acquired immune deficiency syndrome (AIDS) associated with human immunodeficiency virus infection (HIV). It may also be a side effect of drugs such as ciclosporin, phenytoin, interferon, spironolactone, and corticosteroids. Malignant forms of hypertrichosis lanuginosa acquisita look exactly the
