melasma

The symptoms of melasma are dark, irregular, well-demarcated, hyperpigmented macules to patches. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration.{{Cite web|url=https://www.aad.org/public/diseases/color-problems/melasma|title=Melasma {{!}} American Academy of Dermatology|website=www.aad.org|access-date=2016-02-25}} Patches can vary in size from {{Convert|0.5|cm|abbr=on|sigfig=1}} to larger than {{Convert|10|cm|abbr=on|sigfig=1}} depending on the person. Its location can be categorized as centrofacial, malar, or mandibular. The most common is centrofacial, in which patches appear on the cheeks, nose, upper lip, forehead, and chin. The mandibular category accounts for patches on the bilateral rami, while the malar location accounts for patches only on the nose and cheeks.{{Cite book|title=Manual of dermatologic therapeutics|last=Arndt, Kenneth A., 1936-|others=Hsu, Jeffrey T. S.|isbn=978-1-4698-7200-1|edition=Eighth|location=[Place of publication not identified]|oclc=953864747|date = 2014-02-05}}

The exact cause of melasma is unknown.

Melasma is thought to be the stimulation of melanocytes (cells in the dermal layer, which transfer the pigment melanin to the keratinocytes of skin) when the skin is exposed to ultraviolet light from the sun. Small amounts of sun exposure can make melasma return to the skin after it has faded, which is why people with melasma often get it again and again, particularly in the summer.

Pregnant women often get melasma, or chloasma, known as the mask of pregnancy. Birth-control pills and hormone replacement therapy also can trigger melasma. The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone treatment.

Genetic predisposition is also a major factor in determining whether someone will develop melasma. People with the Fitzpatrick skin type III or greater from African, Asian, or Hispanic descent are at a much higher risk than others. In addition, women with a light brown skin type who are living in regions with intense sun exposure are particularly susceptible to developing this condition.

The incidence of melasma also increases in patients with thyroid disease.{{Cite journal | pmid = 3923030| year = 1985| last1 = Lutfi| first1 = R. J.| title = Association of melasma with thyroid autoimmunity and other thyroidal abnormalities and their relationship to the origin of the melasma| journal = The Journal of Clinical Endocrinology and Metabolism| volume = 61| issue = 1| pages = 28–31| last2 = Fridmanis| first2 = M| last3 = Misiunas| first3 = A. L.| last4 = Pafume| first4 = O| last5 = Gonzalez| first5 = E. A.| last6 = Villemur| first6 = J. A.| last7 = Mazzini| first7 = M. A.| last8 = Niepomniszcze| first8 = H| doi = 10.1210/jcem-61-1-28}} It is thought that the overproduction of melanocyte-stimulating hormone brought on by stress can cause outbreaks of this condition. Other rare causes of melasma include allergic reaction to medications and cosmetics.

Melasma suprarenale (Latin: 'above the kidneys') is a symptom of Addison's disease, particularly when caused by pressure or minor injury to the skin, as discovered by FJJ Schmidt of Rotterdam in 1859.{{Citation needed|date=March 2021}}

The two different kinds of melasma are epidermal and dermal.

• Epidermal melasma results from melanin pigment that is elevated in the suprabasal layers of the epidermis.{{Citation needed|date=March 2021}}

• Dermal melasma occurs when the dermal macrophages have an elevated melanin level.{{Cite book|title=Evidence-based dermatology|others=Williams, Hywel C.,, Bigby, Michael E.|isbn=978-1-118-35762-0|edition=Third|location=Chichester, West Sussex|oclc=867001321|date = 2014-06-05}} Melasma is usually diagnosed visually or with assistance of a Wood's lamp (340–400 nm wavelength).{{Cite journal|last1=Handel|first1=Ana Carolina|last2=Miot|first2=Luciane Donida Bartoli|last3=Miot|first3=Hélio Amante|date=2014|title=Melasma: a clinical and epidemiological review|journal=Anais Brasileiros de Dermatologia|volume=89|issue=5|pages=771–782|doi=10.1590/abd1806-4841.20143063|issn=0365-0596|pmc=4155956|pmid=25184917}} Under Wood's lamp, excess melanin in the epidermis can be distinguished from that of the dermis. This is done by looking at how dark the melasma appears; dermal melasma appears darker than epidermal melasma under the Wood's lamp.

The severity of facial melasma may be assessed by colorimetry, mexametry, and the melasma area and severity index (MASI) score.

Melasma should be differentiated from freckles, solar lentigo, toxic melanoderma, Riehl melanosis, post-inflammatory hyperpigmentation, friction melanosis, ochronosis (endogenous and exogenous), and cutaneous erythematosus lupus. Additionally, it should not be confused with phytophotodermatosis, pellagra, endogenous phototoxicity, nevus of Ota, café au lait macules, seborrheic keratosis, Poikiloderma of Civatte, acquired bilateral nevus of ota-like macules (Hori's nevus), periorbital hyperpigmentation, erythrose pigmentaire peribuccale of Brocq, erythromelanosis follicularis faciei, facial acanthosis nigricans, and actinic lichen planus.

Also, cases of drug-induced pigmentation have been reported, caused by amiodarone, or hydroquinone-induced exogenous ochronosis (see ochronosis treatment).

File:Laser Melasma Treatment.jpg laser]]

Assessment by a dermatologist can help guide treatment. Treatments to hasten the fading of the discolored patches include:

• Topical depigmenting agents, such as hydroquinone (HQ) either in over-the-counter (OTC – 2%) or prescription (4%) strength.{{cite journal |last1=Jutley |first1=Gurpreet Singh |last2=Rajaratnam |first2=Ratna |last3=Halpern |first3=James |last4=Salim |first4=Asad |last5=Emmett |first5=Charis |date=2014-02-01 |title=Systematic review of randomized controlled trials on interventions for melasma: an abridged Cochrane review |journal=Journal of the American Academy of Dermatology |volume=70 |issue=2 |pages=369–373 |doi=10.1016/j.jaad.2013.07.044 |issn=1097-6787 |pmid=24438951}} HQ inhibits tyrosinase, an enzyme involved in the production of melanin.
• Tretinoin,{{cite journal |last1=Rivas |first1=Shelly |last2=Pandya |first2=Amit G. |date=2013-10-01 |title=Treatment of melasma with topical agents, peels and lasers: an evidence-based review |journal=American Journal of Clinical Dermatology |volume=14 |issue=5 |pages=359–376 |doi=10.1007/s40257-013-0038-4 |issn=1179-1888 |pmid=23881551|s2cid=30637840 }} a retinoid, increases skin cell (keratinocyte) turnover. This treatment is not used during pregnancy due to risk of harm to the fetus.
• Azelaic acid (20%) is thought to decrease the activity of melanocytes.{{Cite journal|last=Breathnach|first=A. S.|date=January 1996|title=Melanin hyperpigmentation of skin: melasma, topical treatment with azelaic acid, and other therapies|url=https://pubmed.ncbi.nlm.nih.gov/8654129/|journal=Cutis|volume=57|issue=1 Suppl|pages=36–45|issn=0011-4162|pmid=8654129}}
• Tranexamic acid by mouth has shown to provide rapid and sustained lightening in melasma by decreasing melanogenesis in epidermal melanocytes.{{cite journal| title = Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial | journal = Lancet | volume = 389 | issue = 10084 | pages = 2105–2116|year=2017 | pmid = 28456509 | pmc = 5446563 | doi = 10.1016/S0140-6736(17)30638-4 }}
• Cysteamine hydrochloride (5%) over-the-counter{{cite journal |last1=Mansouri |first1=P. |last2=Farshi |first2=S. |last3=Hashemi |first3=Z. |last4=Kasraee |first4=B. |date=2015-07-01|title=Evaluation of the efficacy of cysteamine 5% cream in the treatment of epidermal melasma: a randomized double-blind placebo-controlled trial |journal=British Journal of Dermatology |language=en |volume=173 |issue=1 |pages=209–217 |doi=10.1111/bjd.13424 |pmid=25251767 |s2cid=21618233 |issn=1365-2133}}{{cite journal |last1=Bleehen |first1=S. S. |last2=Pathak |first2=M. A. |last3=Hori |first3=Y. |last4=Fitzpatrick |first4=T. B. |date=1968-02-01 |title=Depigmentation of skin with 4-isopropylcatechol, mercaptoamines, and other compounds |journal=The Journal of Investigative Dermatology |volume=50 |issue=2 |pages=103–117 |issn=0022-202X |pmid=5641641 |doi=10.1038/jid.1968.13|doi-access=free }} Mechanism of action seems to involve inhibition of melanin synthesis pathway{{cite journal |last1=Qiu |first1=L. |last2=Zhang |first2=M. |last3=Sturm |first3=R. A. |last4=Gardiner |first4=B. |last5=Tonks |first5=I. |last6=Kay |first6=G. |last7=Parsons |first7=P. G. |date=2000-01-01 |title=Inhibition of melanin synthesis by cystamine in human melanoma cells |journal=The Journal of Investigative Dermatology |volume=114 |issue=1 |pages=21–27 |doi=10.1046/j.1523-1747.2000.00826.x |issn=0022-202X |pmid=10620110|doi-access=free }}
• Kojic acid (2%) OTC
• Alpha Arbutin 2–5% OTC
• Flutamide (1%){{cite journal |last1=Adalatkhah |first1=Hassan |last2=Sadeghi-Bazargani |first2=Homayoun |date=2015-01-01 |title=The first clinical experience on efficacy of topical flutamide on melasma compared with topical hydroquinone: a randomized clinical trial |journal=Drug Design, Development and Therapy |volume=9 |pages=4219–4225 |doi=10.2147/DDDT.S80713 |issn=1177-8881 |pmc=4531037 |pmid=26345129 |doi-access=free }}
• Chemical peels{{cite journal |last1=Chaudhary |first1=Savita |last2=Dayal |first2=Surabhi |date=2013-10-01 |title=Efficacy of combination of glycolic acid peeling with topical regimen in treatment of melasma |url= https://jddonline.com/articles/dermatology/S1545961613P1149X |journal= Journal of Drugs in Dermatology |volume=12 |issue=10 |pages=1149–1153 |issn=1545-9616 |pmid=24085051}}
• Microdermabrasion to dermabrasion (light to deep){{Cite web|title=Melasma: Diagnosis and treatment|url=https://www.aad.org/public/diseases/a-z/melasma-treatment|access-date=2020-10-19|website=www.aad.org|language=en}}
• Galvanic or ultrasound facials with a combination of a topical crème/gel, either in an aesthetician's office or as a home massager unit
• Laser but not intense pulsed light (which can make the melasma darker)
• Melatonin helps regulate melasma.{{cite web |url=https://www.stanfordchem.com/melatonin-powder-bulk.html |title=Melatonin Powder |website=Stanford Chemicals |access-date=Aug 20, 2024}}{{cite journal |last1=Ma |first1=Li-Ping |last2=Liu |first2=Meng-Meng |last3=Liu |first3=Bo |year=2023 |title=Melatonin inhibits senescence-associated melanin pigmentation through the p53-TYR pathway in human primary melanocytes and the skin of C57BL/6 J mice after UVB irradiation |journal=J Mol Med (Berl) |volume=101 |issue=5 |pages=581-593 |doi=10.1007/s00109-023-02301-y |pmc=10163137 |pmid=37032347}}

Evidence-based reviews found that the most effective therapy for melasma includes a combination of topical agents. Triple combination creams formulated with hydroquinone, tretinoin, and a steroid component have shown to be more effective than dual combination therapy or hydroquinone alone.{{Cite journal|last1=Rajaratnam|first1=Ratna|last2=Halpern|first2=James|last3=Salim|first3=Asad|last4=Emmett|first4=Charis|date=2010-07-07|title=Interventions for melasma|url=http://www.cochrane.org/CD003583/SKIN_treatments-for-melasma-darker-than-normal-skin-occurring-in-patches|journal=Cochrane Database of Systematic Reviews|issue=7|pages=CD003583|language=en|doi=10.1002/14651858.CD003583.pub2|pmid=20614435|issn=1465-1858|url-access=subscription}} More recently, a systematic review found that oral medications also have a role in melasma treatment, and have been shown to be efficacious with a minimal number and severity of adverse events. Oral medications and dietary supplements employed in the treatment of melasma include tranexamic acid, Polypodium leucotomos extract, beta‐carotenoid, melatonin, and procyanidin.{{Cite journal|last1=Zhou|first1=Linghong Linda|last2=Baibergenova|first2=Akerke|date=2017-09-01|title=Melasma: systematic review of the systemic treatments|journal=International Journal of Dermatology|language=en|volume=56|issue=9|pages=902–908|doi=10.1111/ijd.13578|pmid=28239840|s2cid=21683251|issn=1365-4632}}

Oral procyanidin combined with vitamins A, C, and E shows promise as safe and effective for epidermal melasma. In an 8-week randomized, double-blind, placebo-controlled trial in 56 Filipino women, treatment was associated with significant improvements in the left and right malar regions, and was safe and well tolerated.{{Cite journal|last=Handog|first=Evangeline|date=2009-07-20|title=A randomized, double-blind, placebo-controlled trial of oral procyanidin with Vitamins A, C, E for melasma among Filipino women|journal=International Journal of Dermatology|volume=48|issue=8|pages=896–901|doi=10.1111/j.1365-4632.2009.04130.x|pmid=19659873|doi-access=free}}

In all of these treatments, the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc oxide, is preferred,{{Cite web|title=Melasma: Tips for managing|url=https://www.aad.org/public/diseases/a-z/melasma-self-care|access-date=2020-10-19|website=www.aad.org|language=en}} because UV-A, UV-B, and visible lights are all capable of stimulating pigment production.

Many negative side effects can go along with these treatments, and treatments often are unsatisfying overall. Scarring, irritation, lighter patches of skin, and contact dermatitis are all commonly seen. Patients should avoid other precipitants, including hormonal triggers. Cosmetic camouflage can also be used to hide melasma.

• Linea nigra

• List of cutaneous conditions

{{Reflist}}

{{Medical resources

| DiseasesDB = 2402

| ICD10 = {{ICD10|L|81|1|l|80}}

| ICD9 = {{ICD9|709.09}}

| ICDO =

| OMIM =

| MedlinePlus = 000836

| eMedicineSubj = derm

| eMedicineTopic = 260

| MeshID = D008548

| SNOMED CT = 36209000

}}

• {{DermNet|colour/melasma}}

{{Diseases of the skin and appendages by morphology}}

{{Pigmentation disorders}}

{{Pregnancy}}

{{Pathology of pregnancy, childbirth and the puerperium}}

{{Infants and their care}}

Category:Disturbances of human pigmentation

Category:Human pregnancy