Dermatology Flashcards
Chondrodermatitis nodularis helicis?
Chondrodermatitis nodularis helicis (CNH) is a common and benign condition characterised by the development of a painful nodule on the ear. It is thought to be caused by factors such as persistent pressure on the ear (e.g. secondary to sleep, headsets), trauma or cold. CNH is more common in men and with increasing age.
Management
- reducing pressure on the ear: foam ‘ear protectors’ may be used during sleep
- other treatment options include cryotherapy, steroid injection, collagen injection
- surgical treatment may be used but there is a high recurrence rate
Skin conditions associated with DM?
Necrobiosis lipoidica
- shiny, painless areas of yellow/red/brown skin typically on the shin
often associated with surrounding telangiectasia
Infection
- candidiasis
- staphylococcal
Neuropathic ulcers
Vitiligo
Lipoatrophy
Granuloma annulare
- papular lesions that are often slightly hyperpigmented and depressed centrally
Spider Naevi
Spider naevi (also called spider angiomas) describe a central red papule with surrounding capillaries. The lesions blanch upon pressure. Spider naevi are almost always found on the upper part of the body.
Spider naevi can be differentiated from telangiectasia by pressing on them and watching them fill. Spider naevi fill from the centre, telangiectasia from the edge .
Around 10-15% of people will have one or more spider naevi and they are more common in childhood. Other associations
- liver disease
- pregnancy
- combined oral contraceptive pill
Bullous pemphigoid features
Bullous pemphigoid is an autoimmune condition causing sub-epidermal blistering of the skin. This is secondary to the development of antibodies against hemidesmosomal proteins BP180 and BP230.
More common in elderly.
Features:
- itchy, tense blisters typically around flexures
- the blisters usually heal without scarring
- there is stereotypically no mucosal involvement (i.e. the mouth is spared)
in reality around 10-50% of patients have a degree of mucosal involvement. It would, however, be unusual for an exam question to mention mucosal involvement as it is seen as a classic differentiating feature between pemphigoid and pemphigus.
Bullous pemphigoid management
Skin biopsy
immunofluorescence shows IgG and C3 at the dermoepidermal junction
Management:
- referral to a dermatologist for biopsy and confirmation of diagnosis
- oral corticosteroids are the mainstay of treatment
- topical corticosteroids, immunosuppressants and antibiotics are also used
