What is
Hyperpigmentation?
Hyperpigmentation is a skin condition where
the skin can become darker in a uniform or non uniform way.
What causes hyperpigmentation?
Hyperpigmentation is generally caused by
melanin overproduction by the skin cells. Hyperpigmentation can be localised
(post inflammatory hyperpigmentation or melasma for instance) or it can be more
diffuse. The most common cause of diffuse hyperpigmentation is metabolic
such as vit B 12 or folic acid deficiencies.
What is melasma?
Melasma is an acquired form of
hyperpigmentation that is seen most commonly on the face. 90% of those with
melasma are women. Exacerbating factors include pregnancy, hormonal
therapy, such as oral contraceptives, and intense sun exposure.
How many women suffer from hyperpigmentation issues in the UK/worldwide?
According to a study in 2016, 5 million
people in the USA and up to 40% of certain populations are affected by melasma.
Who is most at risk of hyperpigmentation?
Melasma is much more common in women and
has a presumptive genetic component, as 48% have reported a positive family
history according to a 2009 survey. Pathophysiology of melasma involves excess
sunlight/radiation which stimulates excess melanin production in the epidermis
and or dermis. Melanocyte numbers are not increased, but they tend to be larger
and more active. This condition is also seen in pregnancy and is possibly
related to hormonal stimulation from melanocyte stimulating hormones, estrogen
and/or progesterone. The exact genes or hormones involved remain unknown.
How has the contraceptive pill been linked
with hyperpigmentation? What contraceptive pills are likely to affect
pigmentation and which ones aren't?
Hormonal contraceptives, most of which
contain norethindrone and norethynodrel combined with estrogen, maintain the
body in a state of "artificial pregnancy" and can cause hormonal,
vascular, metabolic, and neurological side effects similar to the effects seen
in pregnancy. Many of these involve the skin. Melasma is frequently seen in
women taking oral contraceptives.
How can we treat and prevent
hyperpigmentation?
It goes without saying that an emphasis on
sun protection must be central to any discussion dealing with treating
hyperpigmentation. Patients must use adequate sunscreen, preferably containing
physical blockers such as titanium dioxide or zinc oxide, on all sun-exposed
skin on a daily basis. Sufferers should practice ultraviolet avoidance by using
physical barriers, such as hats and clothing that will reduce exposure.
Hydroquinone is often considered the
topical “gold standard”. Retinoids may also be made and azelaic acid
(AzA), may be combined with a topical corticosteroid. Triple combination fixed
therapy (fluocinolone acetonide 0.01%, hydroquinone 4%, tretinoin 0.05%) has
become a standard intervention as well, with evidence suggesting that the
combination is more effective than hydroquinone monotherapy. Numerous case reports
and studies have been performed over the last decade highlighting the use of
products, such as zinc, arbutin, kojic acid, vitamin C base compounds, and
green tea extracts, as newer therapies for treating melasma patients.
Second‐line therapy consists of the
addition of chemical peels, although these must be used cautiously so as not to
induce further post inflammatory changes. Superficial chemical peels
are generally effective for the management of melasma when properly applied.
Standard options include glycolic acid 20-70%, salicylic acid 20-30%,
trichloroacetic acid (TCA) 10-25%, or Jessner’s solution. Pre treatment with a
course of hydroquinone 4% topically (if available) is thought to improve
outcomes.
Laser therapy can be effective for hyperpigmentation
but must be particularly used with caution in patients with melasma
Lastly, for women who note the onset of
melasma after beginning oral contraceptives, the medication should be stopped
if possible.