freckle
Introduction
Freckle Introduction Freckles (Ephelis, Ephelides, Freckles) are pigmented spots that are common in small yellow-brown or brown pigmentation on the face. They are autosomal dominant, especially in summer, and the development of lesions is related to sun exposure. Often appearing in the forehead bridge of the nose and cheeks, etc., occasionally appear on the back of the neck and shoulders. basic knowledge Sickness ratio: 0.5% Susceptible people: no specific population Mode of infection: non-infectious Complications: skin disease
Cause
Freckle cause
Genetic factors (40%):
For autosomal dominant genetic diseases, the same pattern of freckles can occur continuously in the same part in a generation. Excessive exposure to sunlight or ultraviolet radiation can promote and aggravate the disease. Chinese medicine believes that kidney water is not honored. Floating water stagnation, or by evil stagnation in blood, exogenous wind evil, wind and fire phase and disease.
Pathogenesis (30%):
Children aged 5-6 years, under the control of autosomal dominant genes, ultraviolet radiation, etc., cause pale, brown or dark brown needles to the lentil-sized spotted pigment spots on the exposed parts of the face, neck, and back of the hand.
Prevention
Freckle prevention
(1) In general, avoid excessive sunlight, and avoid excessive sun exposure. Especially in summer, you should pay attention to sun protection or use sunscreen to avoid close marriage.
(2) Eat more fresh fruits and vegetables rich in vitamin C and vitamin E.
(3) Avoid eating photosensitizing drugs and foods, such as: psoralen, methoxypsoralen and so on.
(4) Maintain a comfortable, pleasant, worry-free, depressed state of mind.
(5) Do not use drugs as appropriate. If necessary, please use the medicine under the guidance of a doctor.
Complication
Freckle complications Complications
Severe cases can also be found in the exposed parts of the back of the hand, the neck, the front and back of the ear, the ear cavity, the shoulder arm and so on. Most of them are symmetrical, mainly affecting the appearance.
Symptom
Freckles Symptoms Common Symptoms Facial Spots Long Spots Pregnancy Chloas Skin Dark Spots Bone Spots Freckles Pregnancy Spots Foreheads Long Pox Melanin Precipitate
The melanin of the basal cell layer increases, and the number of melanocytes does not increase. The melanocytes in the lesion are strongly positive for dopa staining of the melanocytes adjacent to the normal skin, and the melanocytes are large and the dendrites are long, in the freckles. The number of melanocytes is large and often rod-shaped.
Clinical manifestation
Freckles are more common in women, appearing in childhood, often appear after 6 to 7 years old, until the most obvious in puberty, every summer, the sun damage is increased, and the winter is reduced.
Skin lesions are light yellow, yellowish brown or brown spots, round, oval or irregular, such as needle tip to grain size, spots are not fused, no symptoms, visible in the exposed parts of the skin, symmetry occurs, especially on the face It is found on the nose, cheeks, back of the hand and upper part of the trunk, but there is no such damage in the palms, soles and mucous membranes.
Examine
Freckle check
Pigment spots are punctate or round, oval, or in various irregular forms, distributed in the face, especially around the nose and cheeks. The size is as large as the tip to the rice, and the diameter is generally less than 2 mm. It is ranging from light brown to dark brown. The number of distribution is small, dozens, many are hundreds, most of them are densely distributed, but they are not integrated. The isolated cloth is scattered around the face. In severe cases, it can also be seen on the back of the hand, neck and ear. Before and after, the exposed parts of the body such as the ear cavity and the shoulder arm are mostly symmetrical.
Histopathology: There is an increase in melanin in the epidermis, but there is no increase in melanocytes. Electron microscopy shows that melanocytes in this area are significantly different from melanocytes in adjacent normal skin, and have a strong performance and a strong dopa-positive reaction. There are more long dendrites, and the melanosomes are long rods.
Diagnosis
Freckle diagnosis
diagnosis
Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.
Differential diagnosis
Although freckles are easily identifiable, some spots are easily confused.
1, the crotch brown cyan, the symmetrical distribution of black and gray spots on the crotch, the boundary is obvious, the number is about 10-20, more common in women. The beauty salon is called dermal spot or sputum, the cause is unclear.
2, freckles-like sputum, the age of onset is about one year old or two years old, the color is deeper than freckles, and has nothing to do with sun exposure, no summer and heavy winter light changes, can occur in any part, pathology shows that the number of melanocytes increases, often one side, general performance For intensive.
3, color dry skin disease, freckle-like pigment spots around the telangiectasia, pigment spots vary in size, uneven depth, uneven distribution, see atrophic spots, photosensitive prominent.
4, face in the middle of freckles-like sputum, rare, often in the first year or so, brown concentrated in the center of the face, accompanied by other deformities, such as epilepsy, low intelligence.
5, pigmentation - intestinal polyps syndrome, pigment spots are black, cheek mucosa more common, not affected by sunlight, often accompanied by polyps.
6, chloasma, light brown to dark brown pigmentation spots symmetrically distributed facial, does not involve the eyelids and oral cavity, the edge is clear or diffuse, sometimes butterfly-winged, more common in women of childbearing age.
