DIAGNOSIS:
The bleb is a fluid collection in bright or sérohématique contents of several millimeters in diameter, superficial. It can sit on the skin and mucous membranes.
It should also evoke a spirit before a post-bullous erosion, a rounded collar epithelial erosion, or significant epidermal peeling like “wet clothes.” Post-bullous erosions are common on the mucous membranes.
The bleb can result either of a intraepidermal cleavage or a cleavage between the dermis and epidermis. On a lesion dating from month 12 hours, a stretched bleb evokes a subepidermal origin, a flaccid balloon and fragile, intraepidermal bleb.
blebs must be distinguished from the vesicles, smaller (1-2 mm diameter), and pustules, collections purulent content.
Examination:
The practitioner should inquire in particular:
– Age of onset of dermatitis;
– Family history of bullous disease;
– Mode of appearance and evolution of blebs (acute, progressive, in spurts); Possible triggering factors (drugs, external agents, pregnancy, sun exposure, etc.).
Clinical examination:
On physical examination, the physician specifies:
– The appearance of blebs (shields, tense, post-bullous erosions); looking for a sign of Nikolski (bullous detachment caused by a push in healthy surrounding skin);
– Their size;
– The topography of blebs, respect or mucosal (oral, genital, conjunctival);
– The appearance of the surrounding skin (healthy, erythematous, inflammatory pseudourticariens closets, etc.);
– A general examination with assessment of impact of the eruption on the general state of hydration status and major functions and possible signs of infection.
An extensive rash, rapidly progressive, impairment of general condition, compromised condition required hospitalization emergency.
Further examination:
In addition to NFS (complete blood count) (search for eosinophilia bullous pemphigoid), the chemistry panel with determination of urea and creatinine (appreciation of the state of hydration), a number of tests More can be done in case of no obvious causes blebs. Rather, they are the responsibility of the specialist.
And may be made:
– A skin biopsy for histology standard on a recent bleb and intact; skin biopsy perilesional healthy skin to direct immunofluorescence;
– Research in the blood of basal antimembrane antibodies and anti-intercellular substance by indirect immunofluorescence, specifying their type (IgG or IgA) and title.
More rarely, may be performed in a specialized environment:
– A Western blot (applied on the patient serum proteins of normal skin) to characterize the circulating antibodies depending on the molecular weight of the proteins recognized;
– An analysis by electron microscopy (often long analysis time);
– IFI (immunofl indirect fluorescence) on human skin cleaved (localization of basal antimembrane antibodies).
ETIOLOGY:
There are basically bullosis by external agent, autoimmune bullous dermatoses, drug eruptions and erythema multiforme.
Bullous disorders by external agents:
These are the most common blebs.
The diagnosis is usually obvious. They do not require additional tests, except for the late cutaneous porphyria.
Physical cause:
Bulb:
The bulb is easily recognized by the patient, after repeated and prolonged friction (wearing new shoes, prolonged walking, etc.).
It must be pierced aseptically. Hydrocolloid dressings (type Compeed®) are available over the counter.
Burns:
Burns can cause bullous lesions reached during the 2nd or 3rd degree. An appreciation of all the intrusion must be made.
If limited reached, the lesions are disinfected by antiseptic chlorhexidine kind in aqueous solution, the bleb advances aseptically leaving the top of the bleb in place, and occlusive dressings applied fatty (e.g., Flammazine®). The same damage can occur after exposure to cold (frostbite).
Important sunburn may contain blebs (equivalent to burning).
Phytophotodermatitis:
Bullous lesions occurring after contact with plant summer or spring after sun exposure, with figurative appearance of lesions (drawings contact areas with plants) evoke phytophotodermatitis.
Symptomatic treatment with topical corticosteroids short course by emollients and lack of sun exposure of recurrence is established.
Bites:
Insect bites and jellyfish can induce bullous lesions. They are obvious diagnosis.
Treatment is symptomatic: Cleaning saline, chlorhexidine antisepsis by possibly applying topical corticosteroids or antihistamines premises.
Caustic:
The application of domestic or industrial caustic (sodium hydroxide, etc.) can cause caustic dermatitis lesions.
The treatment is the same as burns.
Cutanea tarda:
The lesions are caused by sun exposure and predominate on the backs of hands.
The man between 30 and 50 years is the most affected.
Alcoholism and infection with hepatitis
C are contributing factors.
Review:
Are noted in the review:
– Bullous lesions and post-bullous erosions in exposed areas, predominantly on the back of the hands;
– Atrophic scars with milia g rains in these same areas;
– Hypertrichosis and hyperpigmentation temporomalaire;
– Skin fragility.
In urine, there is a massive elimination uroporphyrins. A hypersidérémie is sought, as well as liver abnormalities.HCV and HIV serology should be performed, a wanted chronic alcoholism. Medications taken are identified, some favoring the occurrence of porphyria.
Treatment:
Treatment involves stopping the alcoholism, the eventual management of HCV infection, medication discontinuation possibly inductors.
The specialist may decide to practice slitting or the power is Nivaquine® at low doses twice a week.
Autoimmune bullous dermatosis:
They are due to an autoimmune skin damage, with the presence of antibody antiépiderme.
Next target of these antibodies, we distinguish autoimmune bullous dermatosis by reaching the dermal-epidermal junction (sousépidermiques, bullous pemphigoid and cicatricial, for example) and bullous dermatosis intraepidermal (pemphigus) by loss of cohesion between keratinocytes (phenomenon from acantholysis).
The patient is entrusted to the specialist.
Subepidermal bullous dermatosis:
Bullous pemphigoid (BP):
PB is the most common autoimmune bullous dermatoses, that to which the practitioner is often confronted. The subject especially older and, to a lesser extent, the subject with neurological disorders are most often affected.
* Physical examination:
The skin disease often begins with a persistent itching and appear pseudo-urticarial inflammatory placards or eczema followed by large blebs, with clear contents, tense, on inflammatory placards or erythematous skin.blebs are bilateral, symmetrical, predominant on the bending faces of the members, the roots of the members, on the antero-internal faces of the thighs and the abdomen. There is usually no mucosal involvement.
* Investigations:
NFS found eosinophilia. The examination of a standard histology bleb shows subepidermal bleb containing eosinophils and dermal inflammatory infiltrate.
There is neither acantholysis (unlike pemphigus) or keratinocyte necrosis (unlike toxidermia). Direct immunofluorescence, linear deposits of IgG and / or C3 along the basement membrane are found. In the blood, there are indirect immunofluorescence basal antimembrane antibody. Their rate is not correlated with disease progression.
* Treatment:
The treatment is the responsibility of the specialist.
Systemic corticosteroids is being replaced by a local corticosteroid corticosteroids very strong activity (type Dermoval®), the application shall be the subject of study. Local care (cleaning saline, sterile piercing blebs) are essential. Anti-H1 antihistamines can help reduce itching. In severe cases, immunosuppressive therapy (azathioprine, mycophenolate mofetil) or biological therapy (rituximab) may be necessary.
Cicatricial pemphigoid:
The elderly are most often affected.
* Physical examination:
Unlike bullous pemphigoid, mucous membranes are preferentially affected:
– Oral reached with gingivitis, stomatitis bullous or erosive;
– Achieved with conjunctival adhesions and risk of blindness from corneal pillowcase;
– Be reached with tracheal stenosis.
The skin is unaffected, mainly the head (scalp) and neck (chronic erosions with depressed scars).
* Investigations:
The standard histology (subepidermal bleb) and direct immunofluorescence (linear deposition of IgG and / or C3 along the basement membrane) are identical to those of the PB.
It is often necessary to use the electron microscope study. Cleaved on human skin, the antibodies bind to the bleb floor (on the roof in the DB). Of basal antimembrane antibodies can be found so inconstant in the blood.
* Treatment:
The treatment is the responsibility of the specialist.
Ocular involvement should be evaluated by a rigorous eye examination. The gravity of the infringement may justify such Endoxan® immunosuppressive therapy. More generally, dapsone (Disulone®) is given as first line. It is important to seek a prior G6PD defi cit and perform regular monitoring of NFS as hemolytic anemia is constantly induced.
Hypersensitivity syndrome can also be induced. The Salazopyrine® can be used as an alternative with monitoring of liver function tests and graded. Intravenous immunoglobulins, mycophenolate mofetil and rituximab have also been proposed.
Dermatitis herpetiformis:
Dermatitis herpetiformis is a rare skin disease in France. Adolescents and young adults are most commonly affected, unlike bullous pemphigoid and cicatricial. It is associated with celiac disease (gluten intolerance).
* Physical examination:
The vesiculobullous lesions predominate on the buttocks, elbows and knees. They have a symmetrical arrangement.The disease progresses in spurts with spontaneous remission period.
Celiac disease is usually asymptomatic here.
* Investigations:
Histology shows bullous lesion sousépidermique with deposits of IgA in the top of the root ball dermal papillae. A biopsy of the small intestine show villous atrophy.
The anti-transglutaminase antibodies may be present.
* Treatment:
Treatment includes gluten-free diet (taking special dietary management) associated with dapsone (Disulone®).Sulfasalazine has been proposed in resistant cases.
Epidermolysis bullosa acquisita:
It is exceptional in adults.
* Physical examination:
On friction areas appear mechanical origin blebs, particularly on the extremities. The blebs are on healthy skin and can leave atrophic scars with milia seed.
* Investigations:
Skin biopsy showed a subepidermal bleb appearance with linear deposition of immuno globulins and complement along the dermoepidermal junction. Antimembrane basal circulating antibodies are possible.
The diagnosis is confirmed by sophisticated histological techniques.
An association with bowel disease and diabetes are possible.
* Treatment:
Treatment is based on the eviction of trauma, colchicine, dapsone, corticosteroids or immunosuppressants. It is difficult and the responsibility of the specialist.
Linear IgA Dermatosis:
It predominates in children. The lesions resemble those of bullous pemphigoid with provision sometimes features rosettes.
Treatment is based on the Disulone® and corticosteroids in resistant cases.
Pemphigoid of pregnancy:
(See eruptions during pregnancy)
_ Intraepidermal bullous dermatoses
This is the group of pemphigus. Typically, the lesions are small blebs, plates, fragile rupturing easily on healthy skin. Mucous membranes can be achieved.
Pemphigus vulgaris:
The average age of adults is affected.
* Physical examination:
Mucosal lesions are often inaugural with oral erosions annoying food (dysphagia) and can lead to dehydration and malnutrition. The skin lesions consist of small blebs, flanges, breaking easily with non-healing erosions. A sign of Nikolski is present.
Itching is moderate or absent. Lesions occur in healthy skin. The trunk and the folds are preferentially affected.
* Investigations:
The standard histological examination of a recent bleb shows intraepidermal suprabasal bleb with epidermal cells that have lost their cohesion (acantholysis). The study direct immunofluorescence healthy surrounding skin shows an epidermal deposition mesh net or mesh of IgG and C3. The antiépiderme antibodies are detectable in the blood in 80% of cases by direct immunofluorescence.
Their rate is correlated with disease activity.
Desmoglein constituting the desmosome is the target protein antibodies.
* Treatment:
Pemphigus is a serious, potentially lethal (10% mortality). In addition to local care, general long-term corticosteroid treatment is often proposed attack. Other treatments are tried when glucocorticoid or corticorésistance (mycophenolate mofetil, rituximab).
Superficial pemphigus:
Achieving the skin here is more superficial, in the stratum corneum. Skin lesions predominate in seborrhoeic areas (mid-thoracic area, upper back), with érythématosquameux aspect, with absence of normal mucosal lesion.
Endemic forms exist, especially in Brazil (pemphigus foliaceus or fogo selvagem) and forms induced by certain drugs (Radical sulhydryl as D-penicillamine or captopril).
The treatment uses the same molecules as pemphigus vulgaris in severe cases.
Some limited attacks can be treated with topical corticosteroids.
Paraneoplastic pemphigus:
It is exceptional and is cited here only for memory. The polymorphism of the lesions is more important, in particular with the possible appearance lichenoid lesions.
Treatment is primarily that of neoplasia.
The specific treatment of the skin disease is not well established (topical steroids or corticosteroids, intravenous immunoglobulin, etc.). Evolution is usually severe.
Eruptions:
(See toxidermia)
This is Stevens-Johnson syndrome, toxic epidermal necrolysis and fixed drug eruption bullous. The sudden onset, rapidly changing, mucosal damage, impaired general condition are possible
Histologically, there is a keratinocyte acantholysis without necrosis, and there is no deposition of IgG and / or C3.
The treatment is described in the section on drug eruptions.
Erythema multiforme:
Erythema multiforme predominates in children and young adults.
Clinical examination:
Mucous membranes are often affected with bullous and erosive lesions (mouth, but glans, with the possibility of conjunctival adhesions). Skin lesions are classical ment rosette with three concentric zones and a center inconstant bullous. The acral areas are preferentially affected (elbows, knees, hands, face).
The disease progresses in spurts with spontaneous recovery within 2 to 3 weeks possible.
Further examination:
Histologically, there is a bleb necrotic keratinocytes, no deposit of IgG and / or C3 in direct immunofluorescence.
Most often, erythema multiforme occurs in response to a recurrent herpes (labialis especially). Mycoplasma pneumoniae infections should be raised in case of pneumonia.
Treatment:
The patient is entrusted to the specialist. In the event of outbreaks caused by herpes recurrences, preventive therapy Zelitrex® (1 cp 500 mg) can be tried for six months.
The mycoplasma infection should be treated. The Disulone® or even Thalidomide® can be tried in background processing.
Bullous dermatosis hereditary:
Hereditary epidermolysis bullosa are rare diseases, due to mutations of genes encoding structural proteins of the dermal-epidermal junction. They are found mainly in the newborn. Several types of different severities exist. Rarely, they prove to adulthood.
Abnormal skin fragility with bullous lesions and erosion on areas of friction shows. Diagnosis is based on clinical, family history, histological electron microscopy study and possibly molecular biology.
The management is the domain of the specialist.