Dermatology Flashcards
Cutaneous manifestation of sarcoid?
Sarcoid granulomas
- 1a hydroxylase activated by M0
- conversion of inactive to active vitamin D
- increased calcium absorption / decreased calcium secretion. PTH suppressed
Lupus Pernio
small black raised papules that may coalesce
Indication of active sarcoid and associated with more severe disease
- responds poorly to topical agents
- increase dose of systemic steroid
ERYTHEMA NODOSUM
Painful erythematous or pigmented lesions which are poorly defined
-LOFGRENS SYNDROME = SARCOID with Erythema Nodosum / Hilar involvement / Arthropathy
Pemphigus - describe
Flaccid blisters
(raised = pemphigoid)
Ig deposition throughout epidermis
(basement membrane = pemphigus)
Treat with high dose steroids
look for mucosal ulceration
long term low dose steroids to maintain remission - 2 years
mortality on treatment 5-15%
Pemphigoid - describe
Cutaenous tense blisters
Ig deposition in basement membrane only and not in epidermis itself
treated with high dose steroids to stimulate remission
Tapering and long term low dose steroids for up to 2 years
Lichen planus
Eczematous outbreak with white lines streaking throughout and ITCHY
See white striae especially in mouth
causes pruritis - steroids if so
self limiting.
Flexor surfaces (esp wrists) (Eczema is on extensor surfaces then moves to flexors)
white lines = WICKHAM’S STRIAE
Koebner phenomen
- follows excoriation lines and scars
(as psoriasis)
Associated: B blockers TZD or indapamide methyl dopa anti-malarials
What are Wickham’s Striae
White lines seen via hand lens pathogenic for lichen planus
What is Koebner’s phenomenon
Rash follows scars or excoriations
- lichen planus
- psoriasis
Scabies
SARCOPTES SCABIEI
Human scabies mite
burrows into epidermis
NOCTURNAL PRURITIS
Pruritis onset 4-6 weeks after infection - hypersensitivity to mite or waste products deposited in skin.
RESULTS IN SECONDARY ECZEMA
See burrows between finger webs and toes
Itchy
penile papules
Widespread itchy macular rash
Residential homes
Hostels
TREATMENT: PERMETHRIN
BOIL WASH / THROW OUT ALL LINEN
Dermatofibroma
White pearly papule
dimples when pinched
benign
occurs post trauma
Excision
- diagnostic to R/O BCC
- cosmetic
Describe a typical syphillitic chancre and its management
- shallow ulceration
- typically painless but not always
typically 6 weeks post infection
management:
Benzylpenicillin single dose IM
Describe a benign epidermal naevus
Typically over shoulder region
pigmented due to melanocyte melanin deposition
may have a white demarcation as well
may have hair
Describe a mangolian blue spot
blue naevus typically on lumbar spine but may also be seen on sclera
Describe naevus flaevum
Port wine stain
When on the face should be investigated for leptomeningeal AVM
Describe the associations of acanthosis nigricans
- Colonic carcinoma
- Addisons
- Cushings
- Hypothyroidism
Deeper pigmentation in creases
Describe the lesions in erythema nodosum
Poorly demarcated tender nodular epidermal lesions
Due to neutrophillic inflammation of adipocytes
Sarcoid
mycoplasma pneumonia
Erythema multiforme
Target lesions
multiple differentials
Roth spots
retinal microhaemorrhages with white centre
multiple pathologies Ig deposition in vasculitis HIV bacterial endocarditis microembolism mycoplasma pneumonia
Janeway Lesions
Bacterial Endocarditis
Palmer SC lesions
Poor demarcated
erythematous
painless
Represent dermal microabscesses secondary to septic embolisation in bacterial endocarditis
Osler nodes
Bacterial Endocarditis
Vasculitic manifestation therefore purpuric in appearance
Painful / tender nodules
Ig deposition throughout
Describe a shingles rash
Vesicular outbreak that then crusts and heals
specific to a dermatome in distribution corresponding to the infected anterior horn
Treat with oral aciclovir n the acute instance
If already crusting treat post herpetic neuralgia with gabapentin 300mg daily and increase to 900mg daily (therapeutic dose)
target dose 3.6g/day
What is impetigo
Superficial infection of the skin by staph aureu / A haemolytic strep
highly contagious
causes maculo-papular vesicular rush with crusting and discharge
topical abx - FUSIDIC ACID
IF WIDESPREAD - FLUCLOX OR ERYTHROMYCIN
What is Pyoderma Gangrenosum
Auto immune necrotising skin condition cuasing blisterin and ulceration over wound sites and sites of trauma
NON HEALING STERILE PAINFUL ULCER
i.e. no response to fluclox
AssociatIons
Inflammatory bowel disease:
Ulcerative colitis
Crohn’s disease
Arthritides:
Rheumatoid arthritis
Seronegative arthritis
Hematological disease: Myelocytic leukemia Hairy cell leukemia Myelofibrosis Myeloid metaplasia Monoclonal gammopathy
Autoinflammatory disease:
Pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA syndrome)
Treatment:
Prednisolone 60mg od
How is Atopic Eczema treated?
Treatment:
Aqueous creams
topical steroids
Calcineurin inhibitor - Tacrolimus in severe or resistant atopic eczema
What is oral hairy leukoplakia?
White painless plaques over the lateral aspects of the tongue.
Cause:
REACTIVATION OF EBV
SIGN OF ?HIV in context of EBV reactivation
mx:
HIV testing
Describe what erythema gyratum ripens looks like and what its associations are
Erythematous rash which appears as concentric rings like wood grains
Associated with Squamous cell carcinoma of the bronchus
