Hyperpigmentation usually can be tr...

Hyperpigmentation usually can be traced to the personality and activity of melanocytes. Part I of this two-part article not absents a suggested approach to patients with increased pigmentation. Part II continues the review of conditions associated with hyperpigmentation.

just discovered Changing, or Symptomatic Localized Lesions

A localized hyperpigmented or irregularly pigmented lesion that is recently made known in onset, arises within a congenital nevus, or causes pain or itching could be a malignant melanoma (Figures 1 end 3). The American Cancer Society has evolveed useful guidelines for identifying suspicious nevi (Table 1) (1) [Evidence horizontal C, consensus/expert guidelines]

When possible, suspicious lesions should be excised totally for pathologic evaluation. If size or location hinders complete excision, incisional biopsy (usually strike biopsy) is performed. (2)

Seborrheic keratoses are localized, benign, hyperplastic, hyperpigmented lesions that may mimic melanomas. The hyperpigmentation is associated with hyperplasia of melanocytes. (3) Experienced physicians usually can differentiate seborrheic keratoses based upon their sharp borders; tan, brown or black color; and typical appearance. These lesions have a "stuck-on" appearance, with a surface that is unpolished and craggy (Figure 4, left) or plane with small keratin "pearls" (Figure 4 right). (4)

If seborrheic keratoses are symptomatic or there is a question about possible malignancy, the lesions should be remov and sent for pathologic evaluation.

Acanthosis Nigricans

Acanthosis nigricans, usually related to insulin resistance or obesity, ranges in appearance from a thickened, brown streaking to a leathery, verrucous, papillomatous lesion (Table 2) The condition commonly befalls on the neck or in skin enclosures (e.g., in the axilla, in a less degree than the breast, at the belt line, in the groin), yet it may develop in other parts of the carcass Patients with this condition may complain that they have a "dirty area" that cannot be cleansed (Figure 5)

Microscopically, acanthosis nigricans is characterized from an increased number of melanocytes, with papillary hypertrophy and hyperkeratosis. (5) Associated hypertrophy and hyperkeratosis cause acanthosis nigricans to be palpable rather than macular.

It is important for physicians to recognize acanthosis nigricans, because the condition can be associated with insulin resistance (as come abouts in type 2 diabetes and polycystic ovary syndrome) obesity and, occasionally, malignancy. impressed sign 2 diabetes is increasing in incidence in the United States, especially among black and hispanic children; 60 to 92 percent of these children have acanthosis nigricans. (6) According to the same study (7) that compared 50 children with stamp 2 diabetes and 50 children with protoplast 1 diabetes, acanthosis nigricans was not away in 86 percent of the children with representation 2 diabetes but in none of the children with archetype 1 diabetes. (7) [Evidence horizontal B, retrospective cohort study]

If a patient rapidly unfolds acanthosis nigricans, especially on the palms or individuals occult malignancy is a possibility. A thorough physical examination, a review of a whole s a complete blood count, fecal mysterious blood testing, and chest radiography should be considered if the patient does not fit the typical clinical pattern of insulin resistance. (8) [Evidence plain C, consensus/expert guidelines] Adenocarcinomas are the chiefly common malignancies found in patients with acanthosis nigricans; the tumors are greatest in number often present in the stomach (60 percent) followed on the colon, ovary, pancreas, rectum and uterus. (9)

Treatment of acanthosis nigricans is directed at the underlying cause, rather than the appearance of the skin. If ready insulin resistance should be managed appropriately. Screening for hypercholesterolemia and coronary artery disease may be appropriate, depending forward the clinical picture.

Melasma

Pregnancy or the use of hormones (eg oral contraceptive pills) can cause melasma, a localized facial hyperpigmentation (Figure 6) Melasma may be seen in patients who take phenytoin (Dilantin). While melasma may regres after pregnancy, it may increase with each following pregnancy and become quite obvious. Because of the facial location, melasma may be quite disturbing to patients.

not seldom called the "mask of pregnancy," melasma (chloasma) differs from the ruborous shine brightly of pregnancy. Histologically, women who have this condition lay open an increased number of melanocytes, with the deposition of additional melanin and a background of solar elastosis, typically onward the cheeks, forehead, and upper lip. (10) Examination using a Wood's light in a darkened place demonstrates enhanced contrast if hyperpigmentation affects the epidermal layer of skin. (11)

Patients with hyperpigmentation of the superficial epidermal layer who desire treatment may attempt a trial of bleaching agents after patch testing elsewhere forward the body to confirm cheap levels of inflammation. Use of bleaching agents forward inflamed skin could lead to postinflammatory changes and further hyperpigmentation.