Definitions–generalities:
- a large and heterogeneous group of diseases. secondary to damage to the various constituents of the skin: the dermis, the epidermis or the dermoepidermal junction.
- Their etiologies are multiple, hereditary or acquired, in the first place toxidermies and autoimmune diseases.
- Diagnosis is usually based on clinical examination and histology, often supplemented by immunological examinations.
Vesicles:
- Relief, translucent lesions, 1 to 2 mm in diameter, containing a clear serosity, located in healthy skin (example: chickenpox) or erythematous skin (example: eczema).
Bubbles:
- Relief injuries larger than vesicles (5 mm to several cm) containing a liquid that may be clear, yellowish, or hemorrhagic, that flows after rupture
Nikolsky's sign:
- Nikolsky sign (bully detachment caused by the gentle friction of healthy skin: in Lyell syndrome).
- Erosion (or exulceration): loss of flat-bottomed surface substance, healing without scarring.
Crusts:
- Visible lesions, secondary to the clotting of a serous exudate, hemorrhagic or purulent, which correspond to an evolutionary stage of different primitive elementary lesions: bubbles, vesicles, pustules.
RECALL OF SKIN STRUCTURE:
- The skin coating has the skin and its appendories.
- The skin is made up, from the outside to the inside, by 3 distinct zones: the epidermis, the dermis and the hypodermis.
1) The epidermis The epidermis is a multi–stratified Malpighian epithelium composed of 5 cell layers:
2) The connective organ dermis consisting of:
- a fundamental substance,
- connective fibers
- cellular elements (fibroblasts, fibrocytes).
3) Hypodermis: It is an adipose tissue divided into lobules by connective spans.
- In the dermis and hypodermis path vascular and nerve formations
4) Appendices: The skin contains various so-called ancillary formations:
– the pilo-sebaceous follicle formed from the hair and sebaceous gland appended to the hair canal. (1,2,3)
– the eccrine and apocrine sweat glands. (4,5)
Pathophysiology:
Interratinocy and JDE junction systems.
- The cohesion of the skin and its solidity are ensured by adhesion systems located, on the one hand between the keratinocytes, on the other hand between the epidermis and the dermis. The main structure for interratinocytic adhesion is the desmosome.
epidermal dermo junction:
Interface between epidermis and dermis The JDE is an adhesion zone between the epidermis and the dermis It is developed by keratinocytes and fibroblasts to adhece the epidermis on the dermis
Bubble-forming mechanisms:
- It is the alteration of these different adhesion systems by various processes that is at the origin of the formation of bubbles.
The loss of interratinocytic adhesion, or acantholysis, leads to the formation of intraepidermal bubbles,
– while the attainment of JDE leads to the formation of a subepidermal bubble.
Epidermal necrosis bubbles: Keratinnocytic necrosis may result from a drug allergy (Lyell syndrome, Stevens-Johnson syndrome) or physical aggression of the epidermis (freezes, second degree burns)
Autoimmune bubbles: The different proteins that make up the junction systems can be targeted by autoantibodies. Antibodies directed against desmosome constituents are the cause of pemphigus. Antibodies directed against JDE components are responsible for autoimmune autoimmune bubble diseases.
Toxin or metabolic bubbles: secondary to the action of a bacterial toxin (staphylococcal exfoliatin). In late skin porphyria, it is an abnormality of the metabolism of heme that causes the accumulation of phototoxic products.
Bubbles by hereditary abnormality. Genetic abnormalities in the synthesis of certain components of adhesion structures are at the root of bubble genodermatosis. This is the case for congenital bubble epidermolysis (dermoepidermal bubbles)
Spongiotic bubbles: All dermatoses with interkerratinocytic edema (spongiosis) can give intraepidermal bubbles associated with hyperpressure and keratocytic suffering. This is the case with acute eczema and certain viral dermatoses
ETIOLOGIC DIAGNOSTIC:
- Any bubble toxidermia requires hospitalization for surveillance, even if minor forms are more common than Lyell and Stevens-Johnson syndromes.
- Guidance:
- patient's age (bubble pemphigoid of the elderly, hereditary bubble epidermolysis, staphylococcal epidermolysis and child Kaposi-Juliusberg syndrome)
- Personal and family history (the existence of family cases for congenital bubble dermatoses), the evolutionary mode (rapidly extensive character being more in favour of toxidermy or infectious origin)
- the existence of associated functional signs (frequent pruritus in bubble pemphigoid),
- the existence of triggers (pregnancy for gestationis pemphigoid, sun exposure for late skin porphyria, drug intakes in bubble toxidermies)
CLINICAL EXAMINATION:
- specify the characteristics of the lesions: the size of the bubbles, the appearance of the underlying skin, the presence of cockroaches in favour of a polymorphic rash, the search for a nikolsky sign, topography of the lesions, mucous lesions and skin signs and extracutaneous.
- the impact of bubble disease: dehydration, undernutrition, overinfection.
- assess the evolution by a daily count of the number of bubbles.
ADDITIONAL REVIEWS:
- The etiological diagnosis:
- Eosinophilia is sought on blood count (NFS) and is a good sign in favor of a bubble pemphigoid.
- Tzanck cytodiagnosis seeks acantholytic cells in favor of pemphigus, or bloated cells for infection with a herpes virus.
- Biopsy of a recent bubble specifies the level of intraepidermal or subepidermal cleavage.
Immunopathological data make it possible to accurately diagnose autoimmune bubble diseases;
- direct immunofluorescence (IFD) examination of a peribullelor skin biopsy
- examination of serum in indirect immunofluorescence (IFI) are looking for the presence of antiepidermis or anti–dermal anti-junction autoantibodies
DIAGNOSIS OF SEVERITY:
- Skin detachment results in a loss of physiological functions of the skin.
- The risks of overinfection, dehydration and undernutrition are correlated with the extent of the detachment and the terrain (existence of defects).
1/ Bully polymorphic erythema:
- Polymorphic erythema is a skin-mucous syndrome.
Clinical signs:
- The typical clinical picture: the occurrence of "cockroach" lesions consisting of several concentric zones with a bubble power plant
- The mucous damage is of varying intensity and frequency: postbullic erosions of the oral mucosa. Genital and conjunctival damage is possible.
- Topography: acrale predominance of lesions (palms, plants).
- The alteration of the general condition is moderate
Etiologies:
- Polymorphic erythema: a syndrome responding to many etiologies involving a mechanism of hypersensitivity.
- Postherpetic polymorphic erythema is the most common
Treatment:
- In addition to local care, it relies on the treatment of the cause when it is found
2/ STEVENS-JOHNSON SYNDROME AND LYELL SYNDROME (OR TOXIC EPIDERMIC NECROLYsis):
Stevens-Johnson syndrome:
- This syndrome is currently close to Lyell syndrome.
- bubble and hemorrhagic lesions of the oral cavity, associated with crusty lesions on the outer side of the lips. Genital lesions are frequently associated, as are conjunctiva lesions that make the severity of the syndrome.
- The general condition is often altered
- Central topography with trunk damage.
- Etiology: drugs
Lyell syndrome:
- It is a severe skin-mucous syndrome, secondary to acute skin necrosis, most often of drug origin.
Clinical signs:
- prodromes with a type of flu-like syndrome.
- The onset is most often brutal, the mucous lesions usually preceding the skin lesions.
- Mucous disease, often severe, involves eye (conjunctivitis, keratitis) and buccopharynga, sometimes associated with severe tracheobronchic, esophageal and genital impairment.
- Skin damage is initially formed by diffuse erythematous lesions or confluent macules evolving in 1 to 3 days towards a skin detachment. The skin then takes on a "wet linen" appearance with Nikolsky's sign.
- significant alteration of the general condition
- visceral damage can be encountered: leukopenia, thrombopenia, anemia, liver and pancreatic, and especially bronchopulmonary impairment of very pejorative prognosis.
Histology: necrosis of the full height of the epidermis with bubbling off-shoulder junction
Treatment:
- Hospitalization in a specialized centre is necessary as soon as the diagnosis is made.
- Treatment is based on appropriate hydroelectrolytic resuscitation, significant protein and caloric intakes, warming measures and particularly rigorous antiseptic care.
3/ BULLES OF INFECTIOUS ORIGIN:
Impetigo:
- Streptococcal (group A b-hemolytic streptococcus) or staphylococcal (golden staphylococcus) is common in children, favoured by poor hygiene and sometimes in the form of small school or family epidemics of the makes it highly contagious.
- very superficial, subcorneal intraepidermal bubbles,
- periorificial topography.
- The bubbles evolve towards the formation of characteristic yellowish honey crusts.
- Staphylococcal epidermolysis
- Staphylococcal epidermolysis, rare in adults, is secondary to the secretion of a toxin by some golden staph.
4/ AUTO-IMMUNES BULLEUSES DISEASES:
- a group of rare diseases whose precise diagnosis requires the use of dermatologists and the prescription of specialized examinationsA/JDE diseases
- The bubble diseases of JDE are multiple and are linked to the production of autoantibodies directed against different proteins that make up JDE.
- Description Type: The Bubble Pemphigoid
- It is the most common autoimmune bubble dermatosis of adults. It occurs mainly in elderly subjects (average age: 75 years). The beginning: non–specific signs: isolated pruritus, eczema or urticarian closets.
- The bubbles are based on an erythematous, urticarian or healthy skin base.
- stretched, solid, clear liquid, large and predominate symmetrically over the trunk and root of the limbs.
- Nikolsky: –
Additional reviews:
- Blood hypereosinophilia.
- Histology shows a subepidermal bubble.
- THE IFD: Linear fixation of IgG and C3 along the JDE.
- IFI: circulating antibodies marking JDE;
Treatment:
- antiseptic baths, hydration and nutrition to compensate for hydroelectrolytic and protein loss.
- Conventional treatment is based on general corticosteroidtherapy or very strong dermocorticoides
4/ PEMPHIGUS:
- Pemphigus are rare autoimmune diseases that affect the skin and mucous membranes.
- The autoantibodies present in the serums of the patients are directed against constituents of the desmosomes.
- There are two main types of pemphigus:
– the vulgar pemphigus, where the cleavage is suprabasal;
superficial pemphigus, where the cleavage is under-horned;
Description Type: The vulgar pemphigus
- young subjects (40 years)
- Often oral mucous onset with extensive and painful post-bubble erosions
- Genital and nasal impairment also frequent
- Non-pruriginous skin damage: flasic bubbles on healthy skin predominant in periungueal, vertebral gutter, face and scalp
- Nikolsky
Additional reviews:
- The diagnosis is confirmed by the histological examination of a recent bubble (deep intra epidermal cleavage.
- IFD: presence of IgG and complement on the surface of keratinocytes: an aspect in "mesh mesh")
- IFI: evidence of circulating IgG antibodies directed against the surface of keratinocytes.
Treatment:
- Local care
- corticotherpie -/ immunosuppressant
5/ BULLEUSES MALADIES OF METABOLIC ORIGIN:
- late skin porphyria
- Skin porphyria are most often hereditary diseases, responsible for the accumulation of photosensitizing porphyrin by enzyme deficits related to the metabolism of heme
6/ EXTERNAL CAUSE BUBBLES:
- Sun
- Chemical: application of caustic products,
- insect bites (prurigo strophulus)
- thermal physical agents (burns or exposure to cold) or mechanical (friction bubbles)
Dr. Laroum's class. C – Faculty of Constantine