Patchy hyperpigmentation of the skin is seen in
- Pellagra on exposed part to sunlight
- Porphyria cutanea tarda
- Scleroderma
- Chloasma
- Butterfly rash on face of sle
- Acanthosis nigricans
- Fixed drug eruptions
- Drugs like Chlorpromazine, crofazimine,heavymetals like bismuth and gold
Acanthosis nigricans is a pigmented velvety thickening of skin
Types of Acanthosis nigricans
- Benign type is seen in - Obesity, Cushing's syndrome, drugs-OCP, nicotinic acid, protease inhibitors
- Malignant type seen in Internal malignancy
Haemochromatosis
Endocrine disorders
- Addison's disease
- Cushing's syndrome
- Ectopic ACTH production.
- Nelson's syndrome is seen in post adrenelectomy cases
Common causes of hyperpigmentation are
- Familial, racial.
- Sunburn.
- Addison'sdisease
- Hemochromatosis
- Peutz-Jeghcrs syndrome.
- Chronic kala-azar.
- clofazimine (red), busulphan.
- Pellagra.
- Chronic arsenical poisoning.
- Facial pigmentation in chloasma or melasma. SLE
- Porphyria (cutanea tarda)
- Face.
- Inside the oral cavity, specially cheeks and palate
- Palmar creases
- General skin surface
- Pressure points
- Normally pigmented area like areola
- Sun exposed area
- Recent scars
- Palms and sole
