Actinic keratosis

Introduction to actinic keratosis Actinickeratosis is a disease characterized by hyperkeratosis caused by long-term sun exposure or ionizing radiation stimulation. It is also called solar keratosis or senile keratosis. It is the most common type. Epithelial precancerous skin lesions occur in men older than middle age, and exposed areas are more common. Clinically, brown or yellow flat papules or plaques are the main manifestations, and a few can be converted into squamous cell carcinoma, but metastasis is extremely rare. Individuals can be treated with topical medication or physical therapy. Early surgical resection is suspected of malignant transformation. basic knowledge The proportion of illness: the incidence rate is about 0.002% - 0.003% Susceptible people: men who are more likely to be middle-aged or older Mode of infection: non-infectious complication:

Causes of actinic keratosis

(1) Causes of the disease

Sunlight, ultraviolet light, radioactive heat, as well as bitumen or coal and its extracts can induce the disease, and the patient's susceptibility plays a decisive role.

(two) pathogenesis

Histopathology can be divided into 3 types: hypertrophic, atrophic, and carcinoma in situ.

Hypertrophic type: The epidermal hyperkeratosis is obvious, and the parakeratosis is incomplete. The acanthal hypertrophy and atrophy exist. The acanthosis cells are disordered and vacuol degeneration. The mitotic figures are more common, but not typical, and there are abnormal cells.

Epidermal atrophy: Atypical cells and keratinocytes with loose spines are visible in the basal layer.

In situ cancer-like type: the epidermis is thickened, the epidermal cells are disorderly arranged and there are atypical cells, and the epidermis and dermis are clearly defined.

The superficial layer of the three types of dermis has obvious elastic degeneration, and there is a medium density infiltration mainly composed of lymphocytes.

Actinic keratosis prevention

Prevention: The occurrence of this disease is closely related to sunlight exposure, especially medium-wave ultraviolet (spectrum is 280-320nm). Therefore, if you work outdoors or often go out, it is best to rub the sunscreen on the skin of the exposed sun, such as 5% titanium dioxide ointment. 5% para-aminobenzoic acid cream and sunscreen. You can also wear an umbrella or a visor while you are out.

Actinic keratosis complications Complication

20% of patients with secondary squamous cell carcinoma, with lesions associated with inflammation, erosion and ulceration, are secondary signs of squamous cell carcinoma.

Symptoms of actinic keratosis common symptoms scaly lesions can be horny lobes, slow growth, light brown spot telangiectasia

1. Susceptible and predilection lesions are more common in middle-aged men exposed to sunlight, such as the face, auricle, back of the hand, etc., male patients with skin lesions can occur in the bald area, the auricle and lower lip, more common in women The forearm extends to the side.

2. The clinical symptoms are limited. They are brown-red or yellow spots or plaques with sharp borders. The diameter from the needle tip is more than 2cm in diameter, most of them are several millimeters. The number is variable, but it can be slightly higher than the leather surface, but there is no obvious high edge. The surface is rough, and the keratinized scales are visible. The scaly is forcibly removed. The base surface underneath is ruddy, uneven, and papillary. Sometimes the skin lesions can be horny, forming a skin angle, and the lesion develops slowly and has no symptoms. There may be telangiectasia around the lesion (Figure 1).

Examination of actinic keratosis

Keratosis

The cause of keratosis is that the keratinized pores are occluded by horn plugs, with pores of keratotic papules, the cause is unknown, some patients have hypothyroidism, or Cushing's Syndrome, and some patients are injected or taking corticosteroids. In the future, this kind of skin disease occurs, usually in patients with atopic tendency, or hereditary, mostly in the same family.

1. Typical skin lesions appear in the hair-prone area, showing a patch-like appearance;

2. Histopathology: hyperkeratosis and papillary hyperplasia, horn cysts are seen, and the tumor cells are composed of basal cells.

Diagnosis and identification of actinic keratosis

According to the clinical manifestations, it is generally not difficult to diagnose, and the diagnosis must be pathologically examined.

Differential diagnosis

1. Seborrheic keratosis has oily scales on the surface, soft texture, smooth surface and no hard surface layer. Histopathology shows the formation of epidermal cysts in the epidermis.

2. Discoid lupus erythematosus has dilated follicular pores and hair follicle horn plugs, and has atrophy, skin lesions are good for facial expression, especially on the cheeks and nose, which is butterfly-like.

3. The malignant freckle-like sputum occurs at the exposed part, which is a pigment spot, which is not higher than the leather surface and can be gradually enlarged. The diameter can reach several centimeters, which is brown or black. About 1/3 of the lesions in the elderly can develop into Malignant melanoma.

4. Should also pay attention to the identification of linear epidermal sputum, squamous cell carcinoma.

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