Dermatitis herpetiformis
Encyclopedia
Dermatitis herpetiformis (DH), or Duhring's disease,Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0. is a chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...

 blistering skin
Human skin
The human skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system. The skin has multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments and internal organs. Human skin is similar to that of most other mammals,...

 condition, characterised by blisters filled with a watery fluid. Despite its name, DH is not related to or caused by herpes virus: the name means that it is a skin inflammation having an appearance similar to herpes.

DH was first described by Dr. Louis Duhring in 1884. A connection between DH and gluten intolerance
Gluten sensitivity
Gluten sensitivity belongs to a spectrum of disorders in which gluten has an adverse effect on the body. It can be defined as a non-allergic and non-autoimmune condition in which the consumption of gluten can lead to symptoms similar to those observed in coeliac disease or wheat allergy .Gluten...

 (celiac disease) was recognised in 1967, although the exact causal mechanism is not known.

The age of onset is usually about 15-40, but DH can also affect children and the elderly. Men and women are equally affected. Estimates of DH prevalence vary from 1 in 400 to 1 in 10000.

Symptoms

Dermatitis herpetiformis is characterized by intensely itch
Itch
Itch is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response...

y, chronic papulovesicular eruptions, usually distributed symmetrically on extensor surfaces (buttocks, back of neck, scalp, elbows, knees, back). The blisters vary in size from very small up to 1 cm across.

The condition is extremely itchy, and the desire to scratch can be overwhelming. This sometimes causes the sufferer to scratch the blisters off before they are examined by a doctor. Intense itching or burning sensations are sometimes felt before the blisters appear in a particular area.

Untreated, the severity of DH can vary significantly over time, it is presumed, in response to the amount of gluten
Gluten
Gluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye...

 ingested.

Dermatitis herpetiformis symptoms typically first appear in the early years of adulthood between 20 and 30 years of age.

Although the first signs and symptoms of dermatitis herpetiformis are intense itching and burning, the first visible signs are the small papules or vesicles that usually look like red bumps or blisters. Sometimes they appear on the face
Face
The face is a central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can, depending on the definition in the human case, include the hair, forehead, eyebrow, eyelashes, eyes, nose, ears, cheeks, mouth, lips, philtrum, temple, teeth, skin, and...

 and along the hairline, and, on occasion, on the shoulder
Shoulder
The human shoulder is made up of three bones: the clavicle , the scapula , and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The major joint of the shoulder is the glenohumeral joint, which...

s, the lower end of the spinal column, and within the mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....

. The rash rarely occurs on other mucous membranes, excepting the mouth or lips. The symptoms range in severity from mild to serious, but they are likely to disappear if gluten ingestion is avoided and appropriate treatment is administered. However, the consumption of aliments that contain gluten as well as oral contraceptives may exacerbate the symptoms.

Dermatitis herpetiformis symptoms are chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...

, and they tend to come and go, mostly in short periods of time. Sometimes, these symptoms may be accompanied by symptoms of coeliac disease
Coeliac disease
Coeliac disease , is an autoimmune disorder of the small intestine that occurs in genetically predisposed people of all ages from middle infancy onward...

, commonly including abdominal pain
Abdominal pain
Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...

 and fatigue.

The rash caused by dermatitis herpetiformis forms and disappears in three stages. In the first stage, the patient may notice a slight discoloration of the skin
Human skin
The human skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system. The skin has multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments and internal organs. Human skin is similar to that of most other mammals,...

 at the site where the lesions appear. In the next stage, the skin lesions transform into obvious vesicles and papules that are likely to occur in groups. Healing of the lesions is the last stage of the development of the symptoms, usually characterized by a change in the skin color. This can result in areas of the skin turning darker or lighter than the color of the skin on the rest of the body
Body
With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...

. Because of the intense itching, patients usually scratch, which leads to the formation of crusts.

Usually, itching and burning are the first symptoms to be experienced in dermatitis herpetiformis, and they may occur up to 12 hours before the rash becomes visible. After the blisters develop, itching and burning may persist to up to 10 days, when they finally begin to crust.

Inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 and pus
Pus
Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...

 formation within the blisters is not specific.

Diagnosis

Dermatitis herpetiformis is often misdiagnosed, being confused with drug eruptions, contact dermatitis
Contact dermatitis
Contact dermatitis is a term for a skin reaction resulting from exposure to allergens or irritants . Phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight....

, dishydrotic eczema (dyshidrosis
Dyshidrosis
Dyshidrosis is a skin condition that is characterized by small blisters on the hands or feet...

), and even scabies
Scabies
Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching...

.

Diagnosis is confirmed by a simple blood test
Blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick....

 for IgA
IGA
Iga or IGA may stand for:-Given name:* a female given name of Polish origin. The name originates from the female given name Jadwiga and stands for gia,or gina in the USA....

 antibodies, and by a skin biopsy in which the pattern of IgA deposits in the dermal papillae
Dermal papillae
In the human skin, the dermal papillae are small, nipple-like extensions of the dermis into the epidermis...

, revealed by direct immunofluorescence
Immunofluorescence
Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on biological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows...

, distinguishes it from linear IgA bullous dermatosis
Adult linear IgA disease
Adult linear IgA disease is an acquired, autoimmune blistering disease that may present with a clinical pattern of vesicles indistinguishable from dermatitis herpetiformis, or with vesicles and bullae in a bullous pemphigoid-like appearance.- See also :...

 and other forms of dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...

. These tests should be done before the patient starts on a gluten-free diet, otherwise they might produce false negatives. If the patient has already started a gluten-free diet (there is a strong relationship with DH and coeliac sprue), it might be necessary for them to come off it for some weeks before the tests can be done reliably.

Treatment

Dermatitis herpetiformis responds well to medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

 and changes in diet.

Dapsone
Dapsone
Dapsone is a medication most commonly used in combination with rifampicin and clofazimine as multidrug therapy for the treatment of Mycobacterium leprae infections . It is also second-line treatment for prophylaxis against Pneumocystis pneumonia caused by Pneumocystis jiroveci Dapsone...

 is an effective treatment for most patients. DH responds to dapsone so quickly (itching is significantly reduced within 2–3 days) that this response may almost be considered diagnostic. However, dapsone treatment has no effect on any intestinal damage (see coeliac disease
Coeliac disease
Coeliac disease , is an autoimmune disorder of the small intestine that occurs in genetically predisposed people of all ages from middle infancy onward...

) that might be present.

Therefore, a strict gluten-free diet
Gluten-free diet
A gluten-free diet is a diet that excludes foods containing gluten. Gluten is a protein found in wheat , barley, rye, malts and triticale. It is used as a food additive in the form of a flavoring, stabilizing or thickening agent, often as "dextrin"...

 must also be followed, and this will usually be a lifelong requirement. This will reduce any associated intestinal damage and the risk of other complications. After some time on a gluten-free diet, the dosage of dapsone can usually be reduced or even stopped, although this can take up to 1 to 3 years.

Dapsone is an antibacterial, and its role in the treatment of DH, which is not caused by bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

, is poorly understood. It can cause adverse effects on the blood, so regular blood monitoring is required.

Dapsone is the drug of choice, but, for patients unable to tolerate dapsone for any reason, the following can be tried, although they are less effective:
  • colchicine
    Colchicine
    Colchicine is a medication used for gout. It is a toxic natural product and secondary metabolite, originally extracted from plants of the genus Colchicum...

  • lymecycline
    Lymecycline
    Lymecycline is a tetracycline broad-spectrum antibiotic marketed by the pharmeceutical company Galderma. It is approximately 5000 times more soluble than tetracycline base and is unique amongst tetracyclines in that it is absorbed by an active transport process across the intestinal wall, making...

  • nicotinamide
    Nicotinamide
    Nicotinamide, also known as niacinamide and nicotinic acid amide, is the amide of nicotinic acid . Nicotinamide is a water-soluble vitamin and is part of the vitamin B group...

  • tetracycline
  • sulfamethoxypyridazine
    Sulfamethoxypyridazine
    Sulfamethoxypyridazine is a sulfonamide antibacterial.It is prescribed for vaginal irritation, and severe acute thrush....

  • sulfapyridine
    Sulfapyridine
    Sulfapyridine, original UK spelling Sulphapyridine, is a sulfonamide antibacterial. At one time it was commonly referred to as M&B....


Pathology

In terms of pathology, the first signs of the condition may be observed within the dermis
Dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...

. The changes that can take place at this level may include edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...

, vascular dilatation, and cellular infiltration. It is common for lymphocytes and eosinophils to be seen. The bullae found in the skin affected by dermatitis herpetiformis are subepidermal and have rounded lateral borders.

When looked at under the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

, the skin affected by dermatitis herpetiformis presents a collection of cells known as neutrophils. They have an increased prevalence in the areas where the dermis and is the closest to the epidermis.

Direct IMF studies of uninvolved skin show IgA in the dermal papillae and patchy granular IgA along the basement membrane. The jejunal mucosa may show partial villous atrophy
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...

, but the changes tend to be milder than in coeliac disease.

Immunological studies revealed findings that are similar to those of coeliac disease in terms of autoantigens. The main autoantigen of dermatitis herpetiformis is epidermal transglutaminase (eTG), a cytosolic enzyme involved in cell envelope formation during keratinocyte differentiation.

Various research studies have pointed out different potential factors that may play a larger or smaller role in the development of dermatitis herpetiformis. The fact that eTG has been found in precipitates of skin-bound IgA from skin affected by this condition has been used to conclude that dermatitis herpetiformis may be caused by a deposition of both IgA and eTG within the dermis. It is estimated that these deposits may resorb after 10 years of following a gluten-free diet. Moreover, it is suggested that this condition is closely linked to genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

. This theory is based on the arguments that individuals with a family history of gluten sensitivity that still consume foods containing gluten are more likely to develop the condition as a result of the formation of antibodies to gluten. These antibodies cross-react with eTG, and IgA/eTG complexes deposit within the papillary dermis to cause the lesions of dermatitis herpetiformis. These IgA deposits can disappear after long-term (up to 10 years) avoidance of dietary gluten. Genetics are thought to play an important role in the development of the condition, as well as environmental factors. Monozygotic twins, for example, have an increased risk of developing dermatitis herpetiformis.
It has been shown that androgen levels may affect the immune system in terms of suppression, leading to a decreased immunity. Some specialists argue that low levels of androgens may trigger this condition.

Complications

DH is an autoimmune disease
Autoimmune disease
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...

, and patients with DH are more likely than others to have thyroid problems
Thyroid disease
-Hyper- and hypofunction:Imbalance in production of thyroid hormones arises from dysfunction of the thyroid gland itself, the pituitary gland, which produces thyroid-stimulating hormone , or the hypothalamus, which regulates the pituitary gland via thyrotropin-releasing hormone . Concentrations of...

 and intestinal lymphoma
Lymphoma
Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...

.

Dermatitis herpetiformis does not usually cause complications on its own, without being associated with another condition. Complications from this condition, however, arise from the autoimmune character of the disease, as an over-reacting immune system is a sign that something does not work well and might cause problems to other parts of the body that do not necessarily involve the digestive system.

Gluten intolerance and the body's reaction to it make the disease more worrying in what concerns the possible complications
Complication (medicine)
Complication, in medicine, is an unfavorable evolution of a disease, a health condition or a medical treatment. The disease can become worse in its severity or show a higher number of signs, symptoms or new pathological changes, become widespread throughout the body or affect other organ systems. A...

. This means that complications that may arise from dermatitis herpetiformis are the same as those resulting from coeliac disease, which include osteoporosis
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...

, certain kinds of gut cancer, and an increased risk of other autoimmune diseases such as thyroid disease
Thyroid disease
-Hyper- and hypofunction:Imbalance in production of thyroid hormones arises from dysfunction of the thyroid gland itself, the pituitary gland, which produces thyroid-stimulating hormone , or the hypothalamus, which regulates the pituitary gland via thyrotropin-releasing hormone . Concentrations of...

.

The risks of developing complications from dermatitis herpetiformis decrease significantly if the patients follow a gluten-free diet. The disease has been associated with auto-immune thyroid disease, insulin-dependent diabetes
Insulin-dependent diabetes mellitus
Insulin-dependent diabetes mellitus is a medical term that describes diabetes mellitus that requires insulin therapy to avoid ketoacidosis...

, lupus erythematosus
Lupus erythematosus
Lupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...

, Sjögren's syndrome
Sjögren's syndrome
Sjögren's syndrome , also known as "Mikulicz disease" and "Sicca syndrome", is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva....

, sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...

, and vitiligo
Vitiligo
Vitiligo is a condition that causes depigmentation of sections of skin. It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress,...

 or alopecia areata.

Notable cases

It has been suggested that French revolutionary Jean-Paul Marat
Jean-Paul Marat
Jean-Paul Marat , born in the Principality of Neuchâtel, was a physician, political theorist, and scientist best known for his career in France as a radical journalist and politician during the French Revolution...

 suffered from DH, leading him to spend much of his time in, and even work from, a bathtub filled with an herbal mixture that he used to calm the sores.

See also

  • Coeliac disease
    Coeliac disease
    Coeliac disease , is an autoimmune disorder of the small intestine that occurs in genetically predisposed people of all ages from middle infancy onward...

  • Gluten-free diet
    Gluten-free diet
    A gluten-free diet is a diet that excludes foods containing gluten. Gluten is a protein found in wheat , barley, rye, malts and triticale. It is used as a food additive in the form of a flavoring, stabilizing or thickening agent, often as "dextrin"...

  • Pemphigus herpetiformis
    Pemphigus herpetiformis
    Pemphigus herpetiformis is a cutaneous condition, a clinical variant of pemphigus that combines the clinical features of dermatitis herpetiformis with the immunopathologic features of pemphigus....

  • List of cutaneous conditions

External links

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