The use of energy-based devices such as lasers and intense pulsed light (IPL) has become increasingly popular for the treatment of unwanted body hair. However, as the use of these devices for hair removal have become more widely used, spontaneous reports of the perception of increased hair growth at sites around previous hair removal has been noted. This rare but notable adverse effect is known as paradoxical hypertrichosis. It was first described in the literature in 2002 following IPL therapy1 and can cause great distress to patients.2,3
Hypertrichosis is a condition in which the hair is longer and denser than what is considered normal for an individual based on their age, sex, ethnicity and location of the body and can be classified based on its distribution (generalised vs. localised), age of onset (congenital vs. acquired) and type of hair (lanugo or vellus vs. terminal).4
While the incidence of paradoxical hypertrichosis ranges from 0.6% to 5.1%,5 its exact prevalence is unknown and it is believed to be underreported.6 It appears to occur with low fluences and has…
