Ulceration and Drug Reactions Flashcards
What is an ulcer?
Break in the continuity of the epidermis so that the underlying dermis is exposed
What can cause ulceration?
Result of self-trauma in pruritic skin disease or as a consequence of diseases that involve the epidermis or dermo-epidermal junction including infections, autoimmune diseases, drug reaction and neoplasia
What does widespread ulceration indicate?
Progression from vesicles and bullae, epidermal separation or epitheliotropic lymphoma
What is epidermal separation caused by?
Severe interface dermatitides
What is epitheliotropic lymphoma?
Epidermis is damaged by invasion by neoplastic lymphocytes
How is ulcerative disease diagnosed?
Skin biopsy specimens ideally of intact primary lesions but if not then excisional biopsies across the margins of lesions should be taken
What are vesicles?
Fluid filled elevations of the skin less than 1 cm in diameter that contain clear fluid
Often transient lesions in haired skin due to the thin epidermis
What is a bullae?
Same as a vesicle but >1cm
How are vesicles classified histologically?
Intra-epidermal or sub-epidermal vesicular dermatitis or sometimes interface dermatitis
What is the aetiology of vesicles and bullae?
Viral infection, irritant chemicals and burns, autoimmune and immune-mediated diseases
How can you recognise drug reactions clinically?
Wide range and can imitate any skin disease but the syndrome caused will be unusual or bizarre which often provides a useful clue
What are the possible presentations of drug reactions?
Urticaria/andioedema, exfolliative erythroderma (red scaly skin), and any autoimmune type of presentation
How is a drug reaction diagnosed?
History of drug exposure, clinical signs of a drug reaction, consistent histopathology and rule-out of other causes
What is the therapy for drug reactions?
Stop the offending drug, supportive/symptomatic measures depending on presentation
