Acanthosis Nigricans
Acanthosis Nigricans
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| Acanthosis Nigricans |
History
¤ A cutaneous marker of insulin resistance states.
¤ skin changes leading to patches of dark , velvety skin.
¤ obesity , insulin resistance and polycystic ovary syndrome (PCOs) are risk factors.
¤ obesity , insulin resistance and polycystic ovary syndrome (PCOs) are risk factors.
¤ Other etiologies: hereditary, endocrine disorders, obesity, drugs, hormonal changes and malignancy.
Seen in blacks > Hispanics > whites
¤ Five types:
° Type I (Familial)
- Exceedingly rare
- Autosomal dominant
- Present at birth or develops during childhood
- Worsens at puberty
- Not associated with an internal cancer
° Type II (Benign AN)
- Associated with various endocrine disorders
- Examples include acromegaly, gigantism, Stein-Leventhal syndrome, Cushing’s, diabetes mellitus, hypothyroidism, Addison’s disease, hyperandrogenic states, and hypogonadal syndromes
° Type III (formerly called Pseudo-AN;
however, this probably is the result of an endocrinopathy, namely insulin resistance)
- Most common form.
- Associated with obesity and insulin resistance states
- Not associated with malignancy
° Type IV (Drug-induced):
- Nicotinic acid, niacinamide, diethylstilbestrol, triazineate, oral contraceptives, testosterone, topical fusidic acid, and glucocorticoids
- Seen in 10% of renal transplant patients
° Type V (Associated with malignancy):
- Rare
- Most often in adults
- Highly suspected if occurs in non-obese male
-Tends to be more widespread and involve mucosal surfaces
- Precedes 18%, accompanies 60%, or follows 22% the internal malignancy
- Most often associated with adenocarcinoma of gastrointestinal tract (60% stomach)
- Also associated with lung and breast adenocarcinoma
- Other cancers also seen.
- Most common form.
- Associated with obesity and insulin resistance states
- Not associated with malignancy
° Type IV (Drug-induced):
- Nicotinic acid, niacinamide, diethylstilbestrol, triazineate, oral contraceptives, testosterone, topical fusidic acid, and glucocorticoids
- Seen in 10% of renal transplant patients
° Type V (Associated with malignancy):
- Rare
- Most often in adults
- Highly suspected if occurs in non-obese male
-Tends to be more widespread and involve mucosal surfaces
- Precedes 18%, accompanies 60%, or follows 22% the internal malignancy
- Most often associated with adenocarcinoma of gastrointestinal tract (60% stomach)
- Also associated with lung and breast adenocarcinoma
- Other cancers also seen.
Signs & Symptoms
¤ Often asymptomatic; skin looks “dirty”
¤ Velvety brown thickening of skin on intertriginous surfaces, most tcommonly the axilla, the neck.
¤ Other sites: genitalia, knuckles, lips, submammary area, umbilicus,eyelids, and conjunctiva.
¤ Often asymptomatic; skin looks “dirty”
¤ Velvety brown thickening of skin on intertriginous surfaces, most tcommonly the axilla, the neck.
¤ Other sites: genitalia, knuckles, lips, submammary area, umbilicus,eyelids, and conjunctiva.
What can be mistaken for acanthosis nigrican ?
- AN can be confused with physiological hyperpigmentation or lichen-simplex chronicus in some patients.
- it is associated with insulin resistance when found in diabetic or obese persons.
Tests
¤ Use history and physical as guide to appropriate workup
Basic Tests:
¤ Check blood glucose and possibly an insulin level.
Other Tests:
¤ Exclude malignancy in non-obese patients with no obvious cause.
¤ Screen for malignancy as appropriate for patients age, risk factors, and symptoms.
¤ Screen for endocrinopathy if suspected.
¤ Exclude malignancy in non-obese patients with no obvious cause.
¤ Screen for malignancy as appropriate for patients age, risk factors, and symptoms.
¤ Screen for endocrinopathy if suspected.
What hormone causes ancathosis nigrican ?
- Insulin , insulin resistance leads to type 2 diabetes , polycystic ovary syndrome and might be a factor in developing acanthosis nigrican.
Management
Management
What is the best treatment for acanthosis nigrican ?
- There is no specific treatment for acanthosis nigrican , your physician can suggest treatment for pain , color and odor of skin as creams , soaps , medication and laser therapy .
¤ Depends on cause:
° Weight loss if obese
° Treat underlying endocrinopathy
° Discontinue offending drug
° Treat underlying malignancy
What creams are best for AN ?
- Keratolytics ( topical tretinon 0.05% , ammonium lactate 12% cream or combination of them).
¤ Topical urea, lactic acid and oral etretinate used with varied success.
Specific therapy:
Urea-containing products may give symptomatic relief.
Follow-up
¤ Varies dependent upon the association with an underlying disorder or disease
Complications and Prognosis
¤ Depends on underlying cause
¤ Obesity related AN improves with weight loss
¤ Endocrinopathy associated AN improves with treatment of underlying disease
¤ Removal of malignancy may be followed by regression of AN.
