PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
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Hyperpigmentation occurs as brown macules or patches, often with a poorly defined border, irregular in outline and usually with little surface change. The basic mechanism in response to various triggers (see 'Causes', below) is melanosis of the epidermal or dermal layer of the skin. A number of inflammatory mediators, including prostanoids, cytokines, chemokines as well as reactive oxygen species, are released during the inflammatory process in the epidermal layer. These stimulate melanocytes to increase the production of melanin. In dermal melanosis, inflammation disrupts the basal layer, causing melanin to be released and trapped in the macrophages of the papillary dermis - a process with the delightful name of pigmentary incontinence.
Pigmentary changes are much more common in darker-skinned individuals of Asian or African origin and pigmentation follows many common inflammatory diseases such as eczema, psoriasis or acne. Where erythema is seen in white individuals, pigmentation occurs in dark-skinned individuals.
Pigmentation due to increased melanin is a dirty brown colour, as opposed to that due to haemosiderin pigmentation following purpura, which is more a rusty brown colour.
Other conditions which may enter into the differential diagnosis include:
- Inflammatory skin conditions. Any inflammatory skin condition involving the dermo-epidermal junction can cause hyperpigmentation - eg, eczema, psoriasis, lichen planus, acne, systemic lupus erythematosus, chronic dermatitis and cutaneous T-cell lymphoma.
- Allergic reactions.
- Iatrogenic. Hyperpigmentation can be a complication of treatment with a fully ablative laser device in dark-skinned patients. (This risk can be reduced by the use of fractional CO2 laser.)
- Drugs. Chlorpromazine, chloroquine and arsenic are all common culprits. Other drugs which occasionally cause hyperpigmentation include tetracycline, bleomycin, doxorubicin, 5-fluorouracil, busulfan, antimalarial drugs and hormones (eg, oestrogen).
- Exposure to ultraviolet light.
- Exposure to chemicals such as silver, gold and arsenic.
- Idiopathic. Occasionally no cause can be identified.
- As with melasma, Wood's light may help to differentiate dermal from epidermal hyperpigmentation, which may help to elucidate the cause.
- Biopsy may be required, especially if there is no identifiable preceding inflammation to account for the pigmentation.
Primary care management
- The condition may resolve in time without additional treatment.
- Avoidance of sun exposure may prevent further hyperpigmentation occurring on the face. Daily use of a high-factor sunscreen may be helpful.
- The underlying cause should be treated if possible.
- Hydroquinone 2% is unlicensed for this indication (and is banned in the UK in commercial skin lightener) but GPs may be requested to continue it once initiated by a consultant, as part of shared care arrangements. The usual considerations concerning the prescription of unlicensed medicines should apply. .
- A retinoid such as tretinoin may be helpful, particularly in sun-damaged skin. Azelaic acid may also be useful.
- A topical steroid may help if there is an underlying inflammatory process but, due to skin thinning, caution should be used in applying steroid creams to the face. Retinoic acid triple therapy has been tried using a combination of steroid, retinoid and 4% hydroquinone but requires further evaluation.
- Other treatments being developed, which have shown some depigmenting activity, include a combination of retinaldehyde (a retinoic acid precursor) and glycolic acid and the peroxidase inhibitor methimazole, which inhibits the production of melanin.
- Concerns about the safety of hydroquinone (principally carcinogenesis and ochronosis - development of bluish-black discolouration of various tissues) has led to the search for other treatments. Large numbers of topical and oral agents are currently being investigated.
When to refer
If the diagnosis is in doubt or the patient requests specialist advice, referral should be considered.
Further reading & references
- Sarkar R, Arora P, Garg KV; Cosmeceuticals for Hyperpigmentation: What is Available? J Cutan Aesthet Surg. 2013 Jan;6(1):4-11. doi: 10.4103/0974-2077.110089.
- Postinflammatory hyperpigmentation, DermNet NZ
- Davis EC, Callender VD; Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol. 2010 Jul;3(7):20-31.
- Davis EC, Callender VD; A review of acne in ethnic skin: pathogenesis, clinical manifestations, and management strategies. J Clin Aesthet Dermatol. 2010 Apr;3(4):24-38.
- Pigmentation disorders; DermNet NZ
- Chloasma; DermNet NZ
- Alsaad KO, Ghazarian D; My approach to superficial inflammatory dermatoses. J Clin Pathol. 2005 Dec;58(12):1233-41.
- Tan KL, Kurniawati C, Gold MH; Low risk of postinflammatory hyperpigmentation in skin types 4 and 5 after treatment with fractional CO2 laser device. J Drugs Dermatol. 2008 Aug;7(8):774-7.
- Arora P, Sarkar R, Garg VK, et al; Lasers for treatment of melasma and post-inflammatory hyperpigmentation. J Cutan Aesthet Surg. 2012 Apr;5(2):93-103. doi: 10.4103/0974-2077.99436.
- Malek J, Chedraoui A, Nikolic D, et al; Successful treatment of hydroquinone-resistant melasma using topical methimazole. Dermatol Ther. 2013 Jan-Feb;26(1):69-72. doi: 10.1111/j.1529-8019.2012.01540.x.
- Rossi AB, Leyden JJ, Pappert AS, et al; A pilot methodology study for the photographic assessment of post-inflammatory hyperpigmentation in patients treated with tretinoin. J Eur Acad Dermatol Venereol. 2011 Apr;25(4):398-402. doi: 10.1111/j.1468-3083.2010.03798.x.
- Taylor SC; Utilizing combination therapy for ethnic skin. Cutis. 2007 Jul;80(1 Suppl):15-20.
- Konda S, Geria AN, Halder RM; New horizons in treating disorders of hyperpigmentation in skin of color. Semin Cutan Med Surg. 2012 Jun;31(2):133-9. doi: 10.1016/j.sder.2012.03.001.
- Skin Pigmentation; Skin Dermatologists
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Laurence Knott
Dr Laurence Knott
Prof Cathy Jackson