Riehl’s Melanosis caused by Henna Dyeing, Skin Barrier Improvement is Important

Henna dyeing has come a hot topic recently as it has been aired on several TV shows. Henna, which is a plant-based hair dye, has been promoted as a ‘natural dye without side effects’ and has been used by many people, but there are many cases of side effects related to it.

A lesion known as a side effect of henna dyeing is the overall darkening of the skin on the face and neck. This pigmented lesion is called Riehl’s melanosis. It is the allergen and chemical ingredients of henna are causing side effects such as pigmentation and rash when they meet the skin. The dark pigmented lesion looks like melasma, but it is slightly different from it. Riehl’s melanosis is a dark grayish-brown pigmented contact dermatitis.

Dr. Donghyuk Song, the owner of L Star Clinic, explained, “Generally, people misunderstand Riehl’s melanosis as simply widen melasma. In this case, it can be distinguished from pigmentation of the eyelid and neckline under the jaw. If those area have pigmentation, we can say it is Riehl’s melanosis.

Riehl’s melanosis is a kind of contact dermatitis which occurs itchy and red due to continuous exposure of causative agent. The skin is getting darker gradually and finally causing pigmentation. It is known as side effect of using henna, but chemical ingredients of common hair dye, cosmetics and perfume also are occurred Riehl’s melanosis. Exposure to UV rays after applying cosmetic or perfume containing certain chemical ingredients is a process like an allergic reaction.

Rieh’l melanosis is a lesion that spreads from the epidermis to the dermis. The collapse of the basal layer of the skin affects the sudden onset of pigmentation in the entire layer of the skin. Melanocytes are created in the lower, basal layer of the epidermis of the skin, and this basal layer collapse and the melanin pigment spreads to the dermis.

According to Dr. Donghyuk Song, when we have inflammation in basal layer, mast cells (cells widely distributed in connective tissue of animals) are stimulated, at that time mast cells secrete histamine and histamine attack collagen type 7 and type 17 which are holding epidermis and dermis at basal layer. Thus, melanocytes spread into dermis and whole area are pigmented. When you apply cosmetic on broken basal layer, the chemical ingredients spread into deep dermis easily and moreover, when skin exposures UV rays, there is chemical reactions.

Except above factors, there is not yet known exactly which ingredients cause Riehl’s melanosis. Dr. Song said geraniol and lemon oil are well-known as causative agents of Reihl’s melanosis, but it is not clearly defined what kind of ingredients and how to occur Reihl’s melanosis. Although it is known that it progresses rather quickly, henna tends to progress slowly over 3 to 4 months, and there are cases where only the chin is pigmented except for the eyelids. It may differ from various causes and by person. So, we need to study more for Riehl’s melanosis.

Riehl’s melanosis is difficult to recover naturally once it occurs, but when it is treated well, there is no tendency to recur like melasma, so it is better to actively treat it.

Dr. Song said, “If you feel itchy or red, in early stage, apply steroid or steroid ointment or anti-histamine as like treating contact dermatitis.”, “Pigment lesion on entire dermis can recover when dermis turn to be healthy condition. So treated melanin in deep dermis and remodel collagen to normalize. To get rid of the problem skin, that is, to remove the protein and replace it with a new one, protein denaturation must occur. A long-pulsed laser of 1064nm does that process. I used to a combination of Q-switched Nd:Yag laser and long pulsed laser to treat, and introduced picosecond laser to reduce treatment sessions.”

If Reihl’s melanosis occurs, you should find out the cause and stop using it to prevent the symptom from getting worsen, but before that, it is the most important to stay away from risky substances that cause symptoms.

Dr. Song advised, “If you have a skin disease like Reihl’s melanosis, it means the skin barrier is broken. Generally, skin recovers by itself in 3 to 5 days, and if you are older, it takes 7 to 9 days naturally. However, if skin barrier collapses, the function of recovery is reduced and dermis can be damaged easily.”, “If you are not to use henna or cosmetic with chemical ingredients, the problem is not occurred. The problem is breaking skin barrier repeatedly in our daily life, so it is important to protect skin barrier.”