Thursday, July 15, 2010

The Asian Dermatologic Patient: Article Review

I ran across this article on Medscape (full reference below):  The Asian Dermatologic Patient: Review of Common Pigmentary Disorders and Cutaneous Diseases.  It is originally from the American Journal of Clinical Dermatology.

The vast majority of my patients are Caucasian and African American, but over the years there has been an increase in Asian and Latino.  So when I see an article like this, I read it, even though it is not in depth as it adds to my knowledge.

The Asian patient ….., photodamage in the form of pigmentary disorders is common. Melasma, freckles, and lentigines are the epidermal disorders commonly seen, whilst nevus of Ota and acquired bilateral nevus of Ota-like macules are common dermal pigmentary disorders. Post-inflammatory hyperpigmentation (PIH) occurring after cutaneous injury remains a hallmark of skin of color.

The article notes that over half the world's population is Asian.  At the time of the 2000 US Census, 4.2% of the US population was reported to be of Asian origin.  This group is projected to double in size by 2050. 

The term Asian refers to people having origins from the Far East, southeast Asia, or the Indian subcontinent.  They are a diverse group with various skin phototypes ranging from Fitzpatrick type III to V in the Chinese and Japanese to type IV and V in Indians and Pakistanis.

The most important issues of Asian skin from my standpoint are the issues of photoaging, problems with pigmentation, tendency to form hypertrophic or keloid scars, and the need to remember they too can develop skin cancers.

 

Here are some key points from the article:

Photoaging in Asians

  • Significant photodamage in the form of epidermal atypia and atrophy, dermal collagen and elastin damage, and pigmentary disorders can occur in skin of color.
  • Both pigmentary changes and wrinkling can be major features of photoaging in Asians. However, moderate-to-severe wrinkling becomes apparent only at about 50 years of age, which is a decade or two later than in age-matched Caucasians.
  • Other cutaneous manifestations of aging ethnic skin include the development of benign cutaneous growths such as dermatosis papulosa nigra, seborrheic keratoses, and the development of solar lentigines.

Disorders of Pigmentation

Post-inflammatory hyperpigmentation (PIH) is a common pigmentary disorder in Asian skin.     The severity of PIH is related to the degree of inflammation and extent of disruption of the epidermo-dermal junction. It may be caused by endogenous inflammatory skin disorders or iatrogenic sources such as lasers. 

Melasma is an acquired symmetric hypermelanosis involving sun-exposed areas commonly seen in Asian middle-aged women. Genetics, UV radiation, pregnancy, hormonal therapies, and other phototoxic drugs are all thought to be contributing etiologic factors and melasma remains a difficult condition to treat.  (photo credit)

Combinations of hydroquinone with topical corticosteroids and tretinoin can be effective first-line treatment of melasma.  Glycolic acid, salicylic acid, and trichloroacetic acid peels are also useful adjuncts to topical treatments in the management of melasma in Asians.

Use of bleaching agents and sunscreens for at least 6 weeks, and preferably for 3 months, prior to any laser or light therapy can help suppress the function of hyperactive melanocytes and reduce the risk of PIH. 

Freckles and lentigines are common benign pigmented lesions seen in Asians.

Nevus of Ota is a dermal melanocytic hamartoma common in Asians, affecting about 0.6% of the population.  It presents as a bluish hyperpigmentation along the distribution of the trigeminal nerve. (photo credit)

Acquired bilateral nevus of Ota-like macules or Hori's macules is a condition that affects 0.8% of the Asian population, and are described as bluish-brown hyperpigmentation typically affecting the bilateral malar regions, forehead, and temples of middle-aged women.

Common Skin Diseases in Asians

Atopic dermatitis (eczema) is a common presenting complaint in all dermatology clinics.  Management of atopic dermatitis is similar in the different ethnic groups, and includes emollients, topical corticosteroids, topical tacrolimus, phototherapy, oral antihistamines, and immunosuppressants in resistant cases.

Acne:  The acne hyperpigmented macule is common in skin of color and persists for an average of 4 months or longer.  Ice-pick scarring or keloidal scarring may also occur.

Hypertrophic and keloid scars are more common in individuals of Asian descent than in their Caucasian counterparts.

Psoriasis was the seventh most common skin condition in a large Asian patient survey conducted in Singapore, but is more commonly seen in Caucasians than in Asians and Africans.  It is very rare in Native Americans and Hispanics.

 

Cutaneous Malignancies in Skin of Color

The incidence of melanoma has been reported to range between 0.2 and 2.2 per 100 000 in Asians.   In skin of color, the most common sites for the development of melanoma are non-sun-exposed areas, such as palmar, plantar, subungual, and mucosal surfaces.

Non-Melanoma Skin Cancer  Basal cell carcinoma (BCC), followed by squamous cell carcinoma (SCC), are the most common skin cancers in Chinese and Japanese individuals.

Mycosis fungoides or cutaneous T-cell lymphoma is the fourth most common skin cancer amongst the Japanese.

Hypopigmented mycosis fungoides, with ill-defined, often pruritic, hypopigmented macules and patches, tends to present in a younger patient population and only in skin of color.  The disorder can often be mistaken for vitiligo, pityriasis alba, tinea versicolor, or post-inflammatory hypopigmentation. Misdiagnosis can delay treatment. There is usually a good response to PUVA, UVB phototherapy, or topical mechlorethamine (chlormethine), but recurrences are common. The overall prognosis is good

 

 

 

 

REFERENCES

The Asian Dermatologic Patient: Review of Common Pigmentary Disorders and Cutaneous Diseases; Am J Clin Dermatol. 2009;10(3):153-168; Stephanie G.Y. Ho; Henry H.L. Chan

Dermatosis Papulosa Nigra; eMedicine Article, Feb 19, 2009; Mehran Nowfar-Rad, MD, Frederick Fish, MD

Nevi of Ota and Ito; eMedicine Article, July 14, 2008; Harvey Lui, MD, Youwen Zhou, MD

Melasma; eMedicine Article, May 28, 2010; Andrew D Montemarano, DO, Hugh Lyford

Keloid and Hypertrophic Scar; eMedicine Article, May 14, 2010; Brian Berman, MD, PhD, Whitney Valins, Sadegh Amini, MD, Martha H Viera, MD

3 comments:

Amruta said...

Hey i m an indian,just today i went to dermatologist,due to a bluish pigmentation on my left lateral facial region around the optical region,he said it is a nevas of ota(which is also mentioend in your post)and he said that laser is the only treatment...i wanted to ask you,that is it safe,and is it that it wont appear ever in my life again and will it give me 100% results??....and its like if i go 4 the treatment i would do it with like a year gap in between the settings cause i study..so in between the time gap will that pigmentation increase??...and is it related to basal cell carcinoma in anyway..or anyother health problem,i researched alot on this topic i am so tensed...and so while i was goggling i came across ur blog post....so thought of askin you,sorry bt it will be very kind of you,if you help me out..2mrw morning i may go 4 my first setting...well even i m a first year medical student.

rlbates said...

You really should ask your physician those questions. I don't give individual medical advice through my blog. Here is a nice Medscape article which should answer most, if not all, your questions (free registration with the site is required): Nevus of Ota

Amruta said...

Well,anyway thanks..i had already asked those questions,but was just quite tensed,so just thought of asking you,well today i did my first setting :)....i have faith in science...keeping my fingers crossed :)