Vesiculo- Bullous Eruptions: The Clinical Significance Of The Pemphigus Group Of Diseases To The Skin
A General Overview
These eruptions comprise a heterogenous group of dermatoses which are seen either as the primary manifestation of several cutaneous disorders, or occur during some stage in the evolution of others. Many drug reactions are characterized by bullous eruptions. The term bullar literally means a water bubble. The bulla literally means a water bubble. The bullar (also called bleb or blister) contains serious fluid which may become purulent or hemorrhagic.
The main pathological factor is disturbance of intercellular coherence in the epidermis or adherence at dermo-epidermal junction. Different mechanisms which bring about these changes:
- Genetically determined defects,
- Cell lysis by chemical or infective agents, or
- Immunological reactions involving very selective sites.
Bullous eruption may be caused by known etiological agents (infections, toxins or allergens), or known causes as in pemphigus and dermatitis herpetiformis. Several points are of diagnostic importance in the clinical examination of bullous lesions. These are:
- Distribution- localized or generalized bullae.
- Type-symmetrical or asymmetrical, grouped or discrete and uniform in type or heterogenous.
- Morphology of the lesions- tense or flaccid, contents, shape and size, crusting or scaling, surrounding erythema, appearance of the bulla when removed and presence of Nickolsky’s sign, e.g, enlargement of the bulla when genile continous pressure is applied on it.
- Involvement of other structures eg, mucous membranes eyes.
- Symptoms- local symptoms like pruritus, pain or paraesthesia and systemic symptoms such as fever and toxemia.
Pemphigus Group Of Diseases
The term “penphigus” (signifying blister) is used for denoting a particular group of dermatoses characterized histologically by intraepidermal bullae and acantholysis. The term acantholysis refers to degeneration of the malpighian cells in which the intercellular fibrils diappear and the cells assume a spherical shape with swelling of the nuclei and condensation of the cytoplasm at the periphery. These cells die and the nucleus becomes pyknotic and fragmented. Based on pathology and clinical characteristics, four types of pemphigus are recognized. Commonest among them is pemphigus vulgaris.
Pemphigus vulgaris: This is characterized by the appearance of crops of bullae and mild to severe constitutional disturbances. It is most probably an autoimmune disorder. It is present all over the world. All ages are affected, though adults in the age group of 25 to 50 suffer more. Pathologically, the bullae are intra-epidermal. The underlying dermis shows infiltration by inflammatory cells. Mouth, face, neck and trunk are the common sites for bullae, though any region may be affected. The lesion may be localized or generalized. The bullae appear in crops without any preceding erythema. It is of huge significance as every part of the world is affected by this skin disease. Quality control measures were not sufficient to keep it out of bay, but is is highly treatable with a low morbidity consequence.
© 2014 Funom Theophilus Makama