Pemphigoid Autoantibodies attack antigens in dermal-epidermal junction Bullous pemphigoid: Affects elderly people It is itchy Flexures are often affected Nikolsky sigh is negative Usually not fatal but risk factors are: Old age The need for high steroid dosage Low serum albumin level

Course: A self-limiting disease and treatment can often be stopped after 1-2 years Complications: Of steroids and immunosuppressives If untreated, discomfort, and fluid loss DDx: Dermatitis herpetiformis Other bullous diseases

Investigations: Immunofluorescence will show IgG & C3 along the basement membrane IgG antibodies in serum against basement membrane zone in 70% of patients Peripheral eosinophilia

Treatment: Potent topical steroids in mild cases In acute phase, systemic steroids: prednisolone 40-60 mg/day Immunesuppressives e.g. azathioprine Pemphigoid gestationis It is pemphigoid that occurs with either: Pregnancy Hydatiform mole or Choriocarcinoma Usually it remits after birth Treatment is by systemic steroids Oral contraceptives should be avoided

Dermatitis herpetiformis: Very itchy chronic subepidermal vesicular disease in which the vesicles are arranged into groups similar to those of herpes simplex. For this reason it is called herpetiformis. Cause: Gluten-sensitive enteropathy is always present, but it is asymptomatic. It is a mild enteropathy. There are antibodies against tissue tranglutaminase, reticulin, gliadin, and endomysium which is a component of smooth muscle.

Presentation: Sites particularly affected are: elbows, knees, buttocks and shoulders. Extremely itchy grouped vesicles which soon break due to scratching leaving grouped excoriations. Course: The condition lasts for decades unless patients avoid gluten entirely Gluten-containing diet examples: wheat, barley, rye Gluten-free diet examples: corn, potatoes, rice, and tapioca Complications: Diarrhea, abdominal pain, anemia, and rarely malabsorbtion DDx: Scabies Excoriated eczema Insect bite Neurodermatitis

Investigations: Biopsy will show the the histology of subepidermal blister Direct Immunofluorescence of uninvolved skin shows granular deposits of IgA and usually C3 Serum antibody tests for anti-endomysial antibodies or tissue transglutaminase can help diagnose the enteropathy Treatment: Gluten-free diet Dapsone or sulfapyridine, although both can cause: severe rashes haemolytic anaemia (especially in those with glucose-6-phosphate dehydrogenase deficiency) leucopenia thrombocytopenia methaemoglobinaemia and peripheral neuropathy   Regular blood checks are therefore necessary

Inherited bullous disorders:   Epidermolysis bullosa: Many types. All are characterized by an inherited tendency to develop blisters after minimal trauma The level of formation of blisters (the level of split) is either intra-epidermal (as in simple epidermolysis bullosa) or subepidermal, which in turn is either in lamina lucida (as in junctional epidermolysis bullosa) or beneath lamina densa (as in dystrophic epidermolysis bullosa)

Cause: Simple epidermolysis bullosa: inherited abnormality in gene responsible for keratin production (keratins 5 and 14). Autosomal dominant Junctional epidermolysis bullosa: mutations in gene responsible for laminin formation. Autosomal recessive 3. Dystrophic epidermolysis bullosa (DEB): There are many subtypes, all of which probably result from abnormalities of collagen VII, the major structural component of anchoring fibrils.

Simple epidermolysis bullosa: Presentation: Simple epidermolysis bullosa: blisters start when baby starts crawling i.e. due to trauma heal without scars because are superficial sweating and ill-fitting shoes worsen the condition nails and mucosae are mildly involved   Treatment: avoiding trauma wearing soft well-fitting shoes and using foot powder large blisters should be picked with a sterile needle and dressed . their roofs should not be removed local antibiotics may be needed

2-Junctional epidermolysis bullosa: This rare and often lethal condition is evident at birth The newborn child has large raw areas and flaccid blisters, which are slow to heal The peri-oral and peri-anal skin is usually involved The nails and oral mucous membrane are usually involved There is no effective systemic treatment. Hopes for the future include adding the normal gene to epidermal stem cells, and then layering these onto the denuded skin.

3-Dystrophic epidermolysis bullosa (DEB): Autosomal dominant DEB: In late infancy On friction sites (knees elbows and nails) Heal with scars and milia Deformed or even lost nails Mouth not affected The only treatment is to avoid trauma and to dress the blistered areas

ii.Autosomal recessive DEB:   ii.Autosomal recessive DEB: In infancy Blisters may fill in blood Heal with scar which can be severe scar so that nails are lost and webs form between digits Hands and feet may become useless balls by losing all fingers and toes Teeth, mouth and upper esophagus are affected (esophageal strictures) Squamous cell carcinoma may develop Treatment is unsatisfactory> it is generally as follows: Minimize trauma Maintain nutrition Prevent contractures and web formation Treat anemia Treat secondary infection