Pigmentation due to drugs or chemicals
Introduction
Introduction to pigmentation caused by drugs or chemicals Drug- or chemical-derived pigmentation (drugorchemical substance-induced hyperpigmentation) is mainly caused by abnormal metabolism in the body or deposition in the skin. The drug binds sulfhydryl groups in the epidermis, activates tyrosinase, and increases melanin synthesis, thereby affecting the formation and distribution of melanin, such as pigment abnormalities caused by arsenic. basic knowledge The proportion of illness: 0.02--0.04% Susceptible people: no special people Mode of infection: non-infectious Complications: vitiligo
Cause
Causes of pigmentation caused by drugs or chemicals
(1) Causes of the disease
The cause is unknown.
(two) pathogenesis
The pathogenesis is still not very clear, and the following possibilities are possible:
1. The diffuse deposition of heavy metals causes changes in skin color caused by the dermis.
2. The drug binds sulfhydryl groups in the epidermis, activates tyrosinase, and increases melanin synthesis, thereby affecting the formation and distribution of melanin, such as pigment abnormalities caused by arsenic.
3. Phenothiazines such as chlorpromazine have a special affinity for melanin in human body.
4. The drug binds to hemoglobin to form methemoglobin, which causes skin color changes, such as dapsone.
5. Non-specific inflammatory reaction of the skin caused by drug allergy, which can cause pigmentation after the inflammation subsides.
Prevention
Prevention of pigmentation caused by drugs or chemicals
Early detection, early diagnosis, and early treatment are important for preventing this disease. Regular checkups during pregnancy should be done to supplement adequate folic acid and other vitamins, which can also reduce the incidence of this disease to some extent.
Complication
Pigmentation complications caused by drugs or chemicals Complications
Arsenic is used for 1 to 20 years and is susceptible to vitiligo.
Symptom
Pigmentation symptoms caused by drugs or chemicals Common symptoms Skin pigmentation is bronzed skin diffuse redness reticular pigmentation plaque hyperkeratosis
Clinical manifestations are divided into the following categories:
1. The phenothiazines such as chlorpromazine are progressively pigmented and accumulative. They are blue-gray and have a long-marsto-purple red color. They are more common in the exposed parts such as the face, neck and back of the hand. They may cause it to adhere to the cornea and lens. turbid.
2. Anti-malarial treatment of long-term use of chloroquine can be seen in the calf front and face and neck blue-gray, hard palate and nail bed also have pigmentation, aminophenol quinoline can produce diffuse pigmentation, flexion side, sclera no yellow stain, cornea and The retina can have pigmentation that affects vision and is irreversible.
3. Anticonvulsants use hydantoin derivatives can produce chloasma pigmentation on the face, more common in women.
4. Cellular Metabolic Inhibitor Busulfan in the treatment of leukemia patients can cause diffuse brown pigmentation in the body, face, chest and abdomen, cyclophosphamide can cause brown pigmentation on the exposed parts of the skin, and involve the nails, the roots of the nails.
5. Oral contraceptives can produce chloasma, because estrogen stimulates melanocytes to secrete melanosomes, and progesterone promotes the transport and dissemination of melanosomes.
6. Chlorpheniramine (chlorophenphenazine) is used to treat leprosy reaction. Patients can have diffuse erythema of the whole body after 2 to 4 weeks of treatment. The first appearance is in the face, the palm is urinary brownish red, and the medication is 2 After ~3 months, the skin is brownish black.
7. The use of arsenic for 1 to 20 years can cause diffuse hyperpigmentation of the whole body skin. It is bronzed with normal raindrop pigmentation or reduced plaque, often accompanied by palmar keratosis, and is susceptible to vitiligo.
8. The long-term use of adrenocorticotropic hormone can produce Addison-like pigmentation. The long-term use of sulfone drugs can produce dark gray pigmentation, and the long-term application of phenolphthalein can cause systemic brown pigmentation.
Examine
Examination of pigmentation caused by drugs or chemicals
Clinical skin examination: starting with blue-gray, long-term light purple-red. More common in the face, neck, back of the hand and other exposed parts, deposited in the cornea and lens can cause turbidity. The hard palate and nail bed are also pigmented. Aminophenol quinoline produces diffuse pigmentation. The flexion side is obvious, and the sclera has no yellow stain. The cornea and retina can be pigmented and affect vision, and are irreversible.
Laboratory examination: Local skin pathology showed excessive hyperplasia of pigment cells.
Diagnosis
Diagnostic diagnosis of pigmentation caused by drugs or chemicals
According to clinical manifestations, the characteristics of skin lesions and pathological characteristics can be diagnosed.
