What Is Dermatitis Herpetiformis?

Herpes-like dermatitis is a relatively rare chronic benign recurrent bullous skin disease with an unknown cause. It is characterized by recurrent attacks, a chronic course of disease, diverse rash shapes, symmetrical distribution, severe itching, and good prognosis. Occurs in 22 to 55 years old. There are often asymptomatic gluten allergic bowel diseases.

Basic Information

nickname: Duhring disease
English name: Dermatitis herpetiformis
Visiting department: dermatology
Multiple groups: 22 to 55-year-old asymptomatic patients with gluten allergic bowel disease
Common locations: Scapula, arms, palate and limb extension

Common causes: The cause of the disease has not yet been determined, it may be immune abnormalities, small bowel disease
Common symptoms: The rash is pleomorphic, clustered or arranged in a ring, Portuguese or earthy pattern, erythema erythema or papules, blisters, pustules, severe itching

Causes of herpes-like dermatitis

The cause of herpes-like dermatitis has not yet been determined, and most scholars believe that the disease is related to immune abnormalities and small bowel disease in patients.

Immune abnormality

IgA was deposited in the skin lesions and normal skin dermis of patients, and they were granular under fluorescent microscope. In addition, special antibodies and immune complexes can be found in the blood of about 70% of patients. All these suggest that herpes-like dermatitis is related to patients with autoimmune abnormalities.

2. Small bowel disease

Most patients have small bowel disease, and most patients have no gastrointestinal symptoms. Only 20% to 30% of patients have bloating, diarrhea, and malabsorption. Routine examination of stool shows more small fat particles, indicating that the patient's intestinal function is abnormal. If patients eat foods containing gluten (commonly known as gluten, also known as gluten), such as wheat, barley, oats, and rye, the patient's skin symptoms and bowel function worsen, which indicates that herpes-like dermatitis patients have sensitivity to gluten .

Clinical manifestations of herpes-like dermatitis

Frequently distributed in the scapula, arms, palate, and extremities of the extremities, the skin lesions are symmetrically distributed. The rash is pleomorphic, clustered or arranged in a ring shape, Portuguese or earthy. It starts as erythematous erythema or small pimples, and quickly turns into millet, pea, or larger blisters. The blisters have a tight wall thickness that is not easy to break, and the Nissl sign is negative. After 1 to 2 days, the blisters turned into pustules. Itching is severe early, especially at night, and new rashes are often inoculated due to scratching. Potassium iodide can aggravate the condition.

Herpes-like dermatitis examination

Laboratory inspection

(1) Eosinophils in the blood increase, and the classification count can reach 0.40.

(2) 25% to 50% potassium iodide ointment is used for patch test. Most patients have local erythema and blisters within 24 hours.

2. Immunological examination

(1) Direct Immunofluorescence Examination: Normal skin or pale erythema appears within 3 mm of the skin lesion. 90% of patients have granular IgA and C3 deposits in the dermal papilla. The blisters are often negative due to the destruction of inflammation.

(2) Serological studies A few patients have elevated serum IgA and decreased IgM. 90% of patients with gluten-sensitive bowel disease often have IgA anti-endomysial antibodies. 36% of patients had anti-reticulum antibody IgG and 2/3 patients had anti-gliadin antibody.

(3) Immunogenetics assay of leukocyte surface histocompatibility antigen (HLA) showed that the positive rates of HLA-B8, HLA-DR3, and HLA-DQw2 were 90%, 95%, and 100%, respectively, 30%, 23 compared with normal % And 40% increased significantly.

3. Histopathological examination

In the early stage of the dermal papilla, there were more neutrophils and eosinophils infiltrating around the capillaries, forming small abscesses mainly composed of neutrophils, so that the collagen fibers were dissolved there, and the top of the nipple was separated from the epidermis, forming a multilocular Blisters. After 36 hours, due to the increased exudation, they merged into a single-room subepidermal bullae. Most eosinophils and neutrophils infiltrate the blood vessels in the dermis, with occasional changes in vasculitis.

Diagnosis of herpes-like dermatitis

According to pleomorphic rash, the blisters are predominantly arranged in a ring shape. They occur in the scapula, buttocks, and extremities of the limbs. They are symmetrically distributed, severe itching, negative Nissl sign, and sometimes with malabsorption. , The dermal papilla has a small neutrophil abscess, IgA is granular, and the sulfone drugs have a good therapeutic effect and can be diagnosed.

Differential diagnosis of herpes-like dermatitis

It should be distinguished from herpes pemphigoid, bullous pemphigoid, erythema erythematosus, and bullous epidermolysis.

Herpes-like Dermatitis Treatment

General treatment

Avoid iodine and bromine-containing drugs (such as Huasu tablets) and foods (such as laver and kelp), and a gluten-free (gluten) diet should be avoided.

2. Systemic treatment

(1) dapsone orally 2 or 3 times a day can relieve itching and other symptoms within 1 to 3 days. If the symptoms do not improve, increase the dose appropriately as directed by your doctor.

(2) Sulfadiazine Non dapsone is effective.

For patients with herpes-like dermatitis treated with dapsone and sulfadiazine, check the blood routine every week before and during the first 4 weeks after treatment, then every 2 to 3 weeks for the next 8 weeks, and then every 12 to Check once every 16 weeks, as agranulocytosis may occur at any time. Hemolytic anemia and methemoglobinemia are the most common side effects. These side effects are very severe in patients with hereditary glucose-6-phosphate dehydrogenase (G6PD) deficiency. Central nervous system or liver toxicity is rare. If dapsone treatment causes hemolysis, obvious cardiopulmonary dysfunction or peripheral neuropathy, you should consider switching to sulfadiazine. Sulfadiazine does not generally cause hemolysis.

Some patients with herpes-like dermatitis can control their condition through strict and long-term (such as 6 to 12 months) gluten-free diet, without or with less medication.

3. Local treatment

Mainly itching, anti-inflammatory and prevention of secondary infections.

Herpes-like dermatitis prevention

Some patients are allergic to gluten. After limiting the gluten diet, the condition can naturally improve. At the same time, foods and drugs containing iodine, bromine and chlorine should be avoided.