Blister or bullous lesions
Introduction
Introduction One of the manifestations of blistering or bullous polymorphic exudative erythema. Polymorphic erythema, also known as exudative polymorphous erythema, is an acute inflammatory skin disease with a complex cause. The rash is pleomorphic, often accompanied by mucosal damage, and its characteristic lesion is iris-like erythema. The disease is prone to spring and autumn and is prone to recurrence. The highest incidence rate is 10-30 years old.
Cause
Cause
The cause is not yet known, and the predisposing factors are:
(1) Infection: It is a common cause, the most common of which is herpes simplex virus infection, and some bacteria, fungi, mycoplasma and protozoal infections can also be induced.
(2) Drugs and certain foods: such as sulfonamide, barbital, antipyrine, vaccines and other drugs and fish and meat that have deteriorated.
(3) Physical factors: such as cold, daylight, radiation, etc.
(4) Some diseases such as malignant tumors, connective tissue diseases and pregnancy, menstruation and so on.
Pathogenesis: It is generally believed that this disease is a foreign antigen that stimulates the specific cytotoxic reaction of the body and causes epidermal cell damage.
Examine
an examination
Related inspection
Blood test herpes simplex virus (HSV) neutralization test
Pre-symptoms may include chills, fever, general malaise and sore throat. The rash occurs within 24 hours and is symmetrically distributed. It occurs around the nose and mouth, the back of the hands and feet, the forearms and the extension of the calves, and is also visible in the trunk. The damage is erythema, papules, maculopapular rash, nodules, blisters, and bullous, blood blister or purpura may occur in severe cases. Often accompanied by itching, pain or burning sensation. Mouth, nose, eyes and external genital mucosa can be affected, redness, blisters and erosions. Clinically, one type of skin lesion is often used, and there are other types of skin lesions. According to the characteristics of skin lesions, the clinical classification is divided into three types.
(a) macula-pap type
This type is most common, starting with round edematous erythema or flat papules, lentils to coins size, bright red color, clear boundaries. The rash spreads telecentrically. After 1-2 days, the center becomes dark purple, or purpura, blisters and even blood blisters appear, forming so-called iris-like or target-shaped damage, which is characteristic damage of this disease. The lesions are symmetrically distributed, and the back of the hand, the forearms, and the ankles are good sites. This type of mucosal damage is less, and the systemic symptoms are mild.
(two) blister - bullous
The damage is mainly caused by clusters or scattered blisters and bullae. Blisters can occur on the basis of erythema. At this time, the center of the lesion is blister, bullae or blood blister, and the blister is surrounded by a dark red halo, which is iris-like. This type is often accompanied by mucous vesicles and erosions in the mouth, nose, and genitals. Systemic symptoms such as joint pain, fever, proteinuria, and increased erythrocyte sedimentation rate may occur.
(3) Severe type
Also known as Stevens-Johnson syndrome. Rapid onset, often with high fever, headache, sore throat, joint pain and general malaise. Lesions are bright red or dark red iris-like erythema or ecchymoses with blisters, bullae or blood blisters, and the Nissl's sign can be positive. Skin lesions can be fused into large pieces and widely distributed. The mouth, nose, eyes, genitals and other parts of the mucous membrane are seriously affected. Blisters in the mouth and nasal mucosa, conjunctivitis, keratitis and corneal ulcers in the eyes, and severe ocular inflammation and blindness. Can also be associated with pneumonia, myocarditis, arthritis, peptic ulcer and liver and kidney damage, etc., with clinical symptoms and signs. Skin lesions can be secondary to infection and even sepsis. This type can cause death due to untimely rescue.
[histopathology]
It can be seen that the keratinocytes are partially necrotic, and the basal cells are liquefied and degenerated to form subepidermal vesicles, intracellular edema and sponge formation. There is a significant change in vasculitis in the upper part of the dermis, with lymphocytes infiltrating around the blood vessels, mixed with neutrophils and eosinophils.
Diagnosis
Differential diagnosis
According to the characteristics of skin lesions, combined with the site of good hair, the general diagnosis is not difficult. Care should be taken to ask the medical history carefully and look for incentives. Need to be identified with the following diseases:
(a) Frostbite: occurs in winter. Occurs in the exposed parts of the hands, feet, auricles, nose and cheeks, the skin lesions are dark red or purple red edematous erythema, severe cases may appear blisters, erosion, but generally no iris-like damage, without mucosal damage.
(B) drug eruption: polymorphic erythema type drug eruption performance can be similar to polymorphic erythema, but there is a clear history of medication, no seasonal and certain good hair.
(C) toxic epidermal necrolysis (Lyell disease): should be differentiated from severe polymorphic erythema. The disease is acute, and after rapid, the rash is initially on the face, neck and chest, and quickly spread to the whole body. The skin lesions are twice burned and the necrosis is loosened. The skin is dark and red, and the Nissl sign is positive.
