The skin and systemic disease Flashcards
What is necrobiosis lipoidica and what does it represent?
This is a waxy, shiny, yellowish area on the shins
It occurs in diabetes
What are the four shin lesions?
Necrobiosis lipoidica
Pretibial myxoedema
Pyoderma gangrenosum
Erythema nodosum
What is pretibial myxoedema?
Symmetrical erythematous shin lesions that are shiny with an orange peel skin. They are caused by hyperthyroidism in Graves
What is pyoderma gangrenosum?
These are rapidly growing painful recurring nodulo-pustular ulcers with tender red/blue overhanging edge often on shins.
They are caused by inflammatory bowel disease, connective tissue disorders and myeloproliferative disorders, 50% are idiopathic
What is erythema nodosum?
This is symmetrical erythematous nodules on the shins that heal without scarring.
Most commonly caused by strep infection, inflammatory bowel disease, sarcoidosis and drugs e.g. penicillins
What is acanthosis nigricans?
This is darkened velvety skin often seen in axillae or on neck.
Commonly caused by diabetes but can indicate underlying GI adenocarcinoma
What is dermatitis herpetiformis?
This is itchy burning blisters on the elbows, scalp, shoulders and ankles
Assocaited with coeliac and responds to gluten free diet
What are the dermatological signs of lupus?
Facial butterfly rash
Photosensitivity (face, dorsum of hands)
What is granuloma annulare?
They are chronic non-infectious inflammatory ring-shaped lesion often on the back of the hands. Cause unknwon
What are some of the causes of itchiness?
Itchy lesions: -scabies -urticaria -Atopic eczema -Dermatitis herpetiformis 22% are caused by systemic things: -iron deficiency -lymphoma -hypo/hyperthyroidism -chronic renal failure
What are the causes of pruritis?
Cancers, lymphoma Hepatic causes - jaundice PBC MS Senile pruritus Thyroid dysfunction Chronic renal failure
Which skin condition can present with generalised itch before presenting?
Bullus pemphigoid - look for scabies burrows between fingers
What are the features of lichens planus?
on flexor aspects Purple Pruritic Poly angular Planar (flat topped) Papules May have white lacy markings
What is the treatment of lichens planus?
Topical steroids
What is the pathogenesis of bullous pemphigoid? How is it diagnosed?
This is an autoimmune blitering disorder where IgG autoantibiodies to basement membrane cause blisters
Diagnosed with Biopsy of edge of blister showing +ve immunoforescence for IgG
