Commonly we see Patients with various facial hyperpigmentation who assume they have Melasma, and we know why. Melasma has gained popularity over the years because skincare enthusiasts and professionals speak about it more often than other kinds of facial hyperpigmentation.
Today, we choose to popularize a more prevalent, yet less spoken of kind- PIGMENTARY DEMARCATION LINES.
What are Pigmentary Demarcation Lines ( PDL )?
Pigmentary demarcation lines (PDL) are abrupt transition lines that separate areas of hyperpigmentation from areas of less pigmentation on normal skin.
Pigmentary demarcation lines are commonly seen in Africans and Japanese and rarely in Caucasians. Usually, PDL affects more women than men.
Causes of Pigmentary Demarcation Lines
The exact cause of Pigmentary Demarcation Lines is still unknown and requires further research, however some notable triggering factors have been identified. These factors are:
1. Hormonal factors: These are changes noticed at puberty, pregnancy and with ageing.
2. Environmental factors: These can include sun and heat exposure following inadequate protective measures.
3. Genetic factors: Genetic predisposition has been observed.
4. Acute illnesses: Chicken pox, typhoid.
Types of Pigmentary Demarcation Lines
Currently, there are 8 subtypes of pigmentary demarcation lines that exist: Subtype A through H.
Subtype A-E affects various aspects of the body while subtype F-H affect the face. Because the facial PDL which mimics Melasma is the major concern of skin of color, we would be focusing on it.
The image below shows the areas of the face where we see the facial subtype F-H.
Facial Pigmentary Demarcation Lines appear as symmetrical, non-patchy hyperpigmentation, seen on both sides of the face, extending from the corners of the eyes to the temples in the pattern of a letter V or W ( refer to the before and after images at the top of this article ), or as a band from the angle of the mouth to the side of the chin. It is often mistaken for melasma because of its similarities but it is definitely not melasma.
Normally, a history of long duration, well defined margins and the absence of any skin lesions as a likely cause of hyperpigmentation would be expected.
Pigmentary Demarcation Lines may be present in childhood and go unnoticed, only to return when triggering factors like puberty or pregnancy come to bear. Some other reported triggering factors for PDL are acute illnesses such as chicken pox and typhoid.
Difference between Pigmentary Demarcation Lines and other hyperpigmentary conditions
• Melasma: Melasma and PDL are quite similar but the difference is that melasma is usually blotchy or patchy and may also occur at different sites of the face such as the forehead, nose and upper lip.
• Post Inflammatory Hyperpigmentation: A prior history of the onset of an Inflammatory event on the affected area would help confirm this diagnosis.
Treatment of Pigmentary Demarcation Lines
It is noted that Pigmentary Demarcation Lines, like melasma, has a high recurring rate with no known permanent cure. It can however be managed successfully for long periods of time without relapse.
• Pigmentary Demarcation Lines developed during pregnancy may regress spontaneously though gradually after delivery, hence treatment is not required.
• Facial Pigmentary Demarcation Lines have been seen to respond very well to topical depigmenting products and chemical peel sessions, as was used in the before and after above.
• Q Switched Alexandrite Laser has also shown promising results.
•A strict, consistent compliance to sun and heat protective measures, should be emphasized, otherwise, other treatment procedures may prove futile.
Finally, facial Pigmentary Demarcation Lines are still an evolving entity and requires further research yet, with a promising response to treatment and long-term symptom free management.
N.B: The above before and after images are of an actual patient of Skin101 Centre. Do not use or distribute without permission.
If you are struggling with Pigmentary Demarcation Lines on any part of your body, all you need to do is call us on 0700SKIN101 or 09086000001 to book an appointment or simply book an appointment https://skin101.ng/appointments/