DERMATOLOGY Flashcards
Vitiligo
Autoimmune which results in loss of melanocytes and depigmentation of skin. Affects 1% typically first presents 20-30 years old.
Peripheries more affected
Trauma may precipitate new lesions- koebners phenomenon.
Associated with type 1 DM, Addison’s disease, thyroid disorders.
Lichen planus
Thought to be immune mediated. Itchy papular rash most common on palms soles genitalia and flexor surfaces of arms. Also in mouth Koebnar phenomenon Oral involvement in 50% Thinning of nail plate Tx is topical steroids
Acne Rosacea
Typically affects nose cheeks and forehead
Flushing is often first symptom
Telangiectasia are common
Later develops into persistent erythema with papules and pustules
Rhiophyma
Blepharitis
Tx topical methronidazole, soolantra-ivermectin
Alopecia areata
Autoimmune
Pityriasis Versicolour
Superficial cutaneous skin infection caused by malassezia fur furfur.
Most commonly effects trunk
Patches may be hypopigmented, pink or brown
May be more noticeable after suntan
Mild pruritus
Topical antifungal/ ketoconazole shampoo for large areas.
Bullous Pemphigoid
Autoimmune- ab develop against hemidesmosomal proteins
More common in elderly Itchy tense blisters around flexures Blisters usually heal without scarring Mouth is often spared Referral to deem for biopsy- igG adnC3 Oral corticosteroids
Pyoderma gangrenosum
Typically on lower limbs Initally small red papule Later deep red necrotic ulcer with a violaceous border May be accompanied by fever, myalgia 50% idiopathic IBD RA SLE Primary binary cirrhosis Oral steroids to tx
Erythema ab igne
Caused by over exposure to IR.
CHARACTERISTICS; reticulate erythematous patches with hyperpig and telangiectasia.
Can develop into squamous skin
Hot water bottles and fires
Polymoprhic eruption in pregnancy
Pruitt can condition associated with last trimester
Lesion often first appear in abdo striae
Mgmt depend on severity; emollients mild potency steroids
Pemphigoid Gestationis
Pruritic blistering lesion
Often develop in peri umbilical region later spreading to the trunk back buttocks and arms
Usually presents in 2nd 3 rd trimester and is rarely seen in the first preg
Oral corticosteroids are usually required
Scabies
Spread by prolonged skin contact
Scariest mite lay eggs in stratum cornermen
Intense pruritus is associated with the delayed type Iv hypersensititvy to mites/eggs- occurs 30days after initial infection
Fts
Widespread pruritus
Linear burrows on the side of fingers, interdigital webs and flexor aspects of the wrist
In infants- face and scalp
Permethrin 5% first line
Pruritus persists up to 4-6 weeks post eradication
Psoriasis
2% prevalence
Red scaly patches on skin
Increased risk of arthritis and cardiovascular disease, metabolic syndrome venous thromboembolism
Subtypes- plaque- most common - extensor surfaces
Flexures- skin smooth
Guttate- triggered by strep infection, multiple red teardrop lesions appear on the body
Pustular - palms and soles
Other fts;
Nail pitting and onycholysis
Arthritis
Seborrhoeic dermatitis
Thought to be caused by proliferation of malassezia furfur. 2% of pop
Fts; eczematous lesions on the sebum rish areas- scalp periorbital auricular and nasolabial folds
Associated with HIV and Parkinson’s
Mgmt; zinc pyrithione , antifungal, topical steroids, difficult to tx.
Leukoplakia
Premalignant condition
Presents as hard white spots on mucous membrane of mouth
More common in smokers
Diagnosis of exclusion- candidiasis and lichen planus should be considered- especially if lesions rub off
Squamous carcinoma of skin
COMMON
Mets are rare
From; excessive exposure to sunlight
Actinic keratosis and bowens disease
Immunosuppressive
Long standing leg ulcers- Marjolins ulcer
Seborrhoeic keratosis
BENGIN EPIDERMAL SKIN LESIONS seen in older Doppler
Large variation of colour from flesh to light brown to black
Have stuck on appearance
Keratotomy plugs may be seen on the surface
Cherry haemangioma
Cherry haemangioma Campbell de Morgan spots- benign skin lesions which contain an abnormal proliferation of capillaries More common with increasing age. Erythematous papular lesions Typically 1-3 mm in size Non blanching Not found on mucous membrane
Spider naevi
Central red papule with surrounding capillaries
Lesion blanch upon pressure
Almost always found on the upper part of the body
10-15% of people will have one or more
Associated with liver disease
Preg
Cocp
Actinic keratoses
Actinic keratoses
Common premalignant skin lesion- due to chronic sun exposure
Small crusty, scaly lesions
May be pink red brown or same colour as skin
Typically on sun exposed areas multiple lesions may be present
Mgmt; prevention of further risk
FU cream 2-3 week course
Topical hydro after to settle inflammation
Topical imiquimod
Basal cell carcinoma
Most common skin cancer
Lesions known as rodent ulcers- slow growth and local invasion
Mets are rare
Sun exposed sites
Initally pearly flesh coloured appearance, rolled up edges, telangiectasia
May ulcerate
Fungal nail infection
Onychomycosis is a fungal infection of the nails.
May be causes by dematophytes- T. Rubrum accounts for 90%
Yeasts- candida
Non derma mounds
Up slightly nails are a common reason for presentation
Thickened rough opaque nails
Nail clippings
Scrapings of the affected nail
Tx is successful in 50-80% of people Diagnosis should be confirmed by micro before tx Oral terbinafine 6 weeks to 3 months for fingernail 3-6 months toenails
Dermatitis heretiforms
Autoimmune blistering of skin associated with coeliac disease
Caused by deposition of IgA in dermis
Itchy vesicular skin lesions of extensor surfaces
Tx by gluten free diet
Dapsone
Guttate psoriasis
More common in children and adolescents
May be prescipitated by a strep infection 2-4 weeks prior
Tear drop papules on the trunk and limbs
Most cases resolve spontaneously within 2-3 months
Ubv phototherapy
Rarely seen on soles
Differential diagnosis for shin lesions
Erythema nodosum
Pretibial myxoedema
PYODERMA GANGRENOSUM
Necrobiosis lipoidica
Erythema nodosum
Symmetrical erythematous tender nodules which heal w/o scarring
Most common causes are strep infections, sarcoidosis, IBD and drugs- penicillin, sulphonamides and oral pill
Pretibial myxoedema
Symmetrical erythematous lesions seen in Graves’ disease
Shiny orange peel skin
Pyoderma gangrenosum
Initially small red papule
Later deep red necrotic ulcers with a violaceous border
Idiopathic in 50% may also be seen in IBD, connective tissue disorders nad myeloprolif disorders
Necrobiosis lipoidica
Shiny painless areas of yellow/ red skin typically on the shin of diabetics
Often associated with telangiectasia
Erythema nodosum
Infammation of sub q fat
Typically causes tender erythematous nodular lesions
Usually occurs over shins- ,at be else here
Usually resolves In6 weeks
Heals without scarring
Causes; Infection- strep, to, brucellosis Systemic- sarcoidosis, IBD, behcets Malignancy Drugs- penicillin sulphonamides and cocp Pregnancy
LICHEN SCLEROSUS
Inflammatory condition which usually affects the genitialia and is more common in elderly females
Itch is prominent
Topical steroids and emollients to tx
Increased risk of vulval cancer
Alopecia areata
Autoimmune causing localised demarcated patches of hair loss. Edge of hair loss exclamation hairs
Hair will regrow in 50% in 1 year. 80-90% eventually.
Impetigo
Superficial bacterial infection caused by strep pyogens or staph aureus.
Features; golden crusted skin lesions typically found around the mouth. Very contagious
Mgmt; limited localised disease
Topical fusiliers acid is first line
Extensive disease oral flucloxacillin
Skin manifestations of SLE
Discoid lupus
Photosensitive butterfly rash
Alopecia
Livedo reticularis
HSV
Two strains 1 and 2.
Primary infection may present with severe gingivostomatitis, cold sores, painful genital ulceration.
Oral acid lover, chlorhexidine mouthwash
C section recommended if you get an attack of herpes after 28 weeks
Eczema in children
15-20% if kids
Typically presents before 6 months but clears in 50% by 5 years, 75% by 10.
In infants face and trunk often effected,
Younger children’s extensor surfaces
Older flexor surfaces
Acanthosis nigricans
I
Occurs mainly in axillary, groin and back of neck and appears as a thickened brown velvety patches of skin.
Skin tags often found in area.
Obesity associated an is the most common type and is often linked to insulin resistance.
Also associated with Cushing syndrome, pcos and drugs like nicotinic acid and systemic corticosteroids, pill.
Rare cases can be a sign of malignancy- stomach cancer.
Keloid scarsmpet
Tumour like lesions that arise from the connectivee tissue of a scar and extend beyond the dimensions of the original wound.
More common in those with dark skin.
Young adults
Sternum most common, shoulder, neck face
Less likely if incisionsa re made along relaxed skin tension lines.
Early tx intra lesion also steroids
Excision is sometimes required.
Keratoacanthoma
Benign epithelial tumour.
More frequent in middle age and no not become more common in increasing age
Looks like a volcano or crater
Initally smooth dome shaped papule
Rapidly grows to become a crater filled with keratin
Spontaneous sregression within 3 months is common, often results in scar. Removed often because difficult clinal you to exclude squamous cell. Removal may prevent scarring.
Acne vulgaris mgmt
Usually in adolescence
Face neck upper trunk
Comedones inflammation and pustules
Mild- open and closed condones with or without inflamm lesions
Mod- wind spread non inflamm- papules and pustules
Severe- extensive inflamm lesions
No role in diet modifications
Fungal nail infections
Onychomycosis- fungal infection
May be caused by dermatophytes- trichophyton rubrum 90%
Yeasts Candida
Non dermatophye mounds
Oral terbinafine
Lichen planus
Skin disorder immune mediated
Itchy , papular rash most common on palms soles genitilia and flexor surfaces of arms
Rash often polygonal in shape white lace pattern on the surface.
Koebner phenomenon
Oral involvement in 50%
Nails; thinning of the plate and lontiduinal ridging
Causes gold, quinine thiazides
Tx topical steroids
6 p’s planus; pruritic, purple papular and polygonal - flexor
Vasulitides
Large vessel
Temporal arteritis
Takaysau ateritis
Medical vessel
Polyarthritis nodosa
Kawasaki disease
Small vessel
ANCA
Henoch schonlein
Venous ulceration
Seen above medial malleolus
ABPI- Normal 0.9-1.2
Below 0.9 arterial disease
Above 1.3 arterial disease
Mgmt
Compression bandage
Oral pentoiftyline- vasodilator
Dermatomyositis
Inflamm disorder causing symmetrical proximal muscle weakness and characteristic skin lesions May be idiopathic or associated with connective tissue disorders or underlying malignany- gastric and ovarian tumors ANA Skin fts Photosensitive Macular rash over back and shoulder Heliotrope rash in periorbital region Gottrons papules- extensor of fingers Nail fold capillary dilatation
Other fts Proximal muscle weakness +- tenderness Raynauds Respiratory muscle weakness Interstitial lung disease Dyspagia Dysphona
Actinic keratoses
Common premalignat skin lesion- consequence of sun exposure Fts; small, crusty, scaly lesions May be skin brown or same colour as skin Typically on sun exposed areas Multiple lesions may be present
Mgmt
5fu
Avoid sun
Lentigo maligna
Type of melanoma in situ.
Typically progresses slowly
Asymmetrical as opposed to symmetrical seen in solar lentigo.
Drug induced lupus
Usually resolves after stopping drug
Fts arthralgia, myalgia, malar rash, pleurisy
Ana positive in 100% dsDNA neg
Most common causes;
Procainamide- anti arrhythmic
Hydralazine- smooth muscle relaxant- HTN tx.
Less common
Isoniazid
Minocyclin
Phenytoin
Eczema herpeticum
Primary infection of the skin by herpes simplex 1 or 2. More commonly seen in children with atopic eczema.
Admission for IV aciclovir.
Rheumatic fever
Develops 2-6 weeks after strep pyogenes infection Fts Erythema marginatum Chorea Polysrthritis Carditis Subcut nodules
Minor
Raised crp esr
Pyrexia
Prolonged PR
Liver disease fts
History of alcohol excess
Stigamata - spider naevi, bruising, palmar erythema, gynecomastia
Evidence of decompensation; as cites, jaundice, encephalopathy
Iron def anaemia
Pallor Koilonychia Strophic glossitis Post cricoid webs Angular stomatitis
Polycythemia
Pruritus after warm bath
Ruddy complexion
Gout
PUD
