Excessive eyelash growth is called eyelash trichomegaly
Information on hypertrichosis and hair removal treatments
Hypertrichosis is an excess hair growth disorder characterized by only abnormally long hair and high hair density as compared to the racial, age or sex group to which the patient belongs. Leaving aside a few exceptions, it is not an androgen related growth and does not have a specific distribution.
Hypertrichosis can be generalized and localized and each of these types can be further sub-divided into congenital and acquired. This classification gives a sub-type of hypertrichosis called localized acquired hypertrichosis.
Trichomegaly is a form of localized acquired hypertrichosis and the term is used to describe isolated excessive hair growth of the eyelashes.
Trichomegaly is a rare manifestation of systemic lupus erythematosus. Hypertrichosis of the eyelashes can also be found in areas of linear scleroderma. This finding has been reported in linear scleroderma with or without accompanying melorheostosis.
Isolated hypertrichosis of the eyelashes has additionally been reported in HIV patients, leukemia or lymphoma patients undergoing interferon treatment, and glaucoma patients treated with the drug latanoprost.
Trichomegaly induced by Acquired Immunodeficiency Syndrome or AIDS
Hypertrichosis of the eyelashes has been seen in patients with Acquired Immunodeficiency Syndrome or AIDS and various other infections including pneumocystis carinii and hepatitis. It was clearly not possible to pinpoint one drug, out of the several that were taken, that could be the cause of such a development.
More recently there were reports of hypertrichosis of the eyelashes in other HIV-affected patients who were usually those with opportunistic infections or Kaposi’s sarcoma. Hypertrichosis of the eyelashes has also been reported with kala-azar or Pitaluga’s sign, which can lead to severe malnutrition.
Trichomegaly induced in leukemia and lymphoma patients on interferon treatment
Hypertrichosis of the eyelashes was reported in a patient with chronic granulocytic leukemia on alpha interferon or IFN-alpha and hydroxyl urea and was ascribed to the interferon. However, the interferon was discontinued three months prior to the notation of increased eyelashes and the excess hair growth disappeared after another three months. This observation did not provide conclusive evidence of a cause and effect for the interferon and hypertrichosis was clearly not proved in this case. However, two other patients with lymphoma treated with IFN-alpha were reported to have developed hypertrichosis of the eyelashes. Three patients with renal or hepatic allografts and one patient with systemic lupus erythematosus were found with hypertrichosis of the eyelashes, three to four months after starting cyclosporine medication. It should be noted that these patients were also taking systemic steroids.
Trichomegaly induced by latanoprost
The topical drug latanoprost, an analogue of prostaglandulin F2 analogue, used to treat topically chronic open-angle glaucoma has been shown to cause regional hypertrichosis of the eyelashes and eyelids in approximately 77 percent of the patients treated with this drug. The hypertrichosis is associated with hyper pigmentation of the eyelashes. The new growth of lash-like hair may include extra rows of eyelashes. These extra eyelashes could well be longer, thicker and darker. This additional growth is typically restricted to the eye under treatment, but a bilateral effect of treatment of one eye and hypertrichosis of the ipsilateral of the ear lobe has been reported. The hypertrichosis was persistent even after the medication was discontinued.
This class of drugs acts by prostanoid self-surface receptors G-proteins linked to phosphorylase C which in turn activates a family of protein kinases. Prostanoid molecules including prosta glandin F-2 alpha bind to these receptors in certain tissues which in turn initiates an intracellular signaling response characterized by an increase in formation of diacylglycerol and inositol triphosphate with subsequent activation of protein kinase C and mobilization of intracellular calcium.
Latanoprost drugs are capable of increasing cell division, up-regulating trophic metabolic activity and increasing tissue growth in the fetus in the pregnancy stage. It is hypothesized that latanoprost acts in one of these mitogenic ways.