[8 min read] Common pigmentary conditions presenting in general practice

Pigmentary conditions present as discolouration of the skin. Typically in the form of patches, blemishes, spots, or freckles. The affected areas can be darker or lighter than the surrounding skin.

These changes are usually benign and non-assignable to a particular cause. For most patients, skin pigmentation disorders are an aesthetic and psychological issue. However, they can sometimes indicate skin malignancy or other underlying conditions.

Proper diagnosis in primary care is invaluable because it enables an appropriate and more efficient treatment.

 

Overview

Skin’s pigmentation depends on ethnic origin. The activity level and quantity of melanocytes, the melanin-producing cells, also play a part.

Hyperpigmentation and hypopigmentation are usual manifestations of pigmentary conditions.

In the skin of colour, melanisation provides better protection from sun damage. Therefore, pigmentary changes may be more worrying. Lighter skin produces less melanin and is prone to sun damage.

Three commonly recorded benign pigmentation disorders in primary care are:

  • Post-inflammatory hyperpigmentation
  • Solar lentigo
  • Melasma

 

Post-inflammatory hyperpigmentation

The cause of pigmentation disorder, in this case, are inflammatory skin conditions such as:

  • Atopic dermatitis
  • Psoriasis
  • Acne
  • Contact dermatitis, and
  • Lichen planus

Other potential causes include allergic rash, trauma, and reactions to certain medications. These include:

  • Tetracycline,
  • Clofazimine,
  • Bleomycin,
  • Doxorubicin,
  • Busulfan, and
  • some antimalarial drugs.

Post-inflammatory hyperpigmentation typically presents as patches of darker skin. These patches follow the same pattern as the initial inflammatory condition. Further darkening is common with exposure to sunlight (UV light). The disorder is more common in people with dark skin.

Skin bleaching is the standard treatment for hyperpigmentation. It is usually a combination of topicals, such as:

  • Hydroquinone,
  • Retinoids,
  • Azelaic acid,
  • Vitamin C,
  • Corticosteroids.

Glycolic acid peels and laser treatment work well too.

 

Solar lentigo

Long-term exposure to sun’s UV radiation causes solar lentigo. These are benign and usually small patches of darker skin, also known as “old age spots”.

Solar lentigo appears in parts of the skin exposed to sunlight, such as the face, shoulders, arms, and hands. The shape of the spots is irregular, and the colour varies from light brown to black. They can be scaly sometimes.

Minimal sun exposure and the use of sunscreen are the best preventive measures. Bleaching is ineffective. Laser removal and cryotherapy work well. However, they can cause permanent skin discoloration in the area.

 

Melasma

Bilateral, brown, macules or irregular patches are the main characteristics of melasma. The condition usually presents on the face. It affects people with a genetic predisposition (family history). However, other factors such as sun exposure and pregnancy also play a part.

Depending on the location and shape of the patches, melasma can be:

  • Malar – cheeks, and nose
  • Mandibular – chin and jawline
  • Centro-facial – upper lip, nose, cheeks, and forehead
  • Erythosis pigmentosa faciei – inflammation and redness
  • Extra-facial – usually on shoulders and arms

Quitting hormonal contraception and using sun protection can improve melasma.

The treatment combination of hydroquinone, tretinoin, and topical steroids is usually the best option. Aggressive chemical peels and laser therapy can make melasma worse or cause post-inflammatory hyperpigmentation.

Diagnosing pigmentary disorders in primary care is challenging at times. Treatment errors that result from inaccurate diagnosis can cost some patients a precious amount of time and more. It is therefore imperative that practitioners can diagnose and manage common pigmentary conditions in primary care.


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References

Zubair R, Lyons AB, Vellaichamy G, Peacock A, Hamzavi I. What’s New in Pigmentary Disorders. Dermatol Clin. 2019 Apr;37(2):175-181. doi: 10.1016/j.det.2018.12.008. Epub 2019 Feb 16. PMID: 30850040.

Shenoy A, Madan R. Post-Inflammatory Hyperpigmentation: A Review of Treatment Strategies. J Drugs Dermatol. 2020 Aug 1;19(8):763-768. doi: 10.36849/JDD.2020.4887. PMID: 32845587.

Imokawa G. Melanocyte Activation Mechanisms and Rational Therapeutic Treatments of Solar Lentigos. Int J Mol Sci. 2019 Jul 26;20(15):3666. doi: 10.3390/ijms20153666. PMID: 31357457; PMCID: PMC6695993.

Sarkar R, Bansal A, Ailawadi P. Future therapies in melasma: What lies ahead? Indian J Dermatol Venereol Leprol. 2020 Jan-Feb;86(1):8-17. doi: 10.4103/ijdvl.IJDVL_633_18. Erratum in: Indian J Dermatol Venereol Leprol. 2020 Sep-Oct;86(5):608. PMID: 31793496.

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