Dermatology Flashcards
What malignancy is Acanthosis nigricans assoc. with?
Acanthosis nigricans - Gastric cancer
what malignancy is Acquired ichthyosis and erythroderma assoc with?
Acquired ichthyosis and erythromderma - Lymphoma
what malignancy is Acquired hypertrichosis lanuginosa assoc. with?
Acquired hypertrichosis lanuginosa - Gastrointestinal and lung cancer
what malignancy is Erythema gyratum repens assoc with?
Erythema gyratum repens - Lung Ca
what malignancy is Dermatomyositis assoc with?
Dermatomyositis - Bronchial and breast ca
what malignancy is Migratory thrombophlebitis assoc. wit?
Migratory thrombophlebitis - Pancreatic cancer
what malignancy is Necrolytic migratory erythema assoc. with?
Necrolytic migratory erythema - Glucagonoma
what malignancy is Pyoderma gangrenosum assoc. with?
Pyoderma gangrenosum - Myeloproliferative disorders
what malignancy is Sweet’s syndrome assoc with?
Sweet’s syndrome - Hematological Ca e.g. Myelodysplasia - tender, purple plaques
What malignancy is Tylosis assoc. with?
Tylosis - Oesophageal cancer
what is polymorphic eruption of pregnancy?
-what trimester is this seen in?
-where do lesions appear?
-what is the management?
Polymorphic eruption of pregnancy
• Pruritic condition associated with last trimester
• Lesions often first appear in abdominal striae
• Management depends on severity: emollients, mild potency topical steroids and oral steroids
may be used
what is pemphigoid gestionus?
-where do these develop?
-what trimester is this assoc. with?
-what is the management?
Pemphigoid gestationis
• Pruritic blistering lesions
• Often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms
• Usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy
• Oral corticosteroids are usually required
• Lupus vulgaris (accounts for 50% of cases)
• Erythema nodosum
• Scarring alopecia
• Scrofuloderma: breakdown of skin overlying a tuberculous focus
• Verrucosa cutis
• Gumma
are all assoc with…
TB
what is the most common form of cutaneous TB? describe the lesion?
Lupus vulgaris is the most common form of cutaneous TB seen in the Indian subcontinent. It generally occurs on the face and is common around the nose and mouth. The initial lesion is an erythematous flat plaque which gradually becomes elevated and may ulcerate later
Describe skin condition in hypothyroid
• Dry (anhydrosis), cold, yellowish skin
• Non-pitting oedema (e.g. hands, face)
• Dry, coarse scalp hair, loss of lateral
aspect of eyebrows
• Eczema
• Xanthomata
Pruritus in both
Describe skin condition in hyperthyroid
• Pretibial myxoedema: erythematous, oedematous lesions above the lateral malleoli
• Thyroid acropachy: clubbing
• Scalp hair thinning
• ↑ sweating
Pruritus in both
Describe the lesions in erythema multiforme
• Target lesions (typically worse on peripheries e.g. Palms and soles)
• Severe = stevens-johnson syndrome (blistering and mucosal involvement)
• Idiopathic
• Bacteria: mycoplasma, Streptococcus
• Viruses: herpes simplex virus, Orf
• Drugs: penicillin, sulphonamides,
carbamazepine, allopurinol, NSAIDs,
oral contraceptive pill, nevirapine
• Connective tissue disease e.g.
Systemic lupus erythematosus
• Sarcoidosis
• Malignancy
are all causes of…
erythema multiforme
what may alopecia be subdivided into?
Alopecia may be divided into scarring (destruction of hair follicle) and non-scarring (preservation of hair follicle)
describe the causes of scarring alopecia
• Trauma, burns
• Radiotherapy
• Lichen planus
• Discoid lupus
• Tinea capitis - scarring would develop in untreated tinea capitis if a kerion develops
• TB
what are the causes of non-scarring alopecia?
• ♂-pattern baldness
• Drugs: cytotoxic drugs, carbimazole,
heparin, oral contraceptive pill,
colchicine
• Nutritional: iron and zinc deficiency
• Autoimmune: alopecia areata
• Telogen effluvium (hair loss following stressful period e.g. Surgery)
• Trichotillomania “hair loss from a patient’s repetitive self-pulling of hair”
what is alopecia areata? what does this cause?
Alopecia areata is a presumed autoimmune condition causing localised, well demarcated patches of hair loss. At the edge of the hair loss, there may be small, broken ‘exclamation mark’ hairs
what is the prognosis of alopecia areata?
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually. Careful explanation is therefore sufficient in many patients.
list the treatment options of alopecia areata?
Other treatment options include:
• Topical or intralesional corticosteroids
• Topical minoxidil
• Phototherapy
• Dithranol
• Contact immunotherapy • Wigs
what are 4 types of shin lesion?
• Erythema nodosum
• Pretibial myxedema
• Pyoderma gangrenosum
• Necrobiosis lipoidica diabeticorum
what is the lesion:
• Symmetrical, erythematous, tender, nodules which heal without scarring
• Most common causes are streptococcal infections, sarcoidosis, inflammatory bowel disease and
drugs (penicillins, sulphonamides, oral contraceptive pill)
erythema nodosum
what is the lesion:
• symmetrical, erythematous lesions seen in Graves’ disease
• shiny, orange peel skin
pretibial myxoedema
what is the lesion:
• Initially small red papule
• Later deep, red, necrotic ulcers with a violaceous border
• Idiopathic in 50%, may also be seen in inflammatory bowel disease, connective tissue disorders
and myeloproliferative disorders
pyoderma grangrenosum
what is the lesion:
• Shiny, painless areas of yellow/red skin typically on the shin of diabetics
• Often associated with telangiectasia
Necrobiosis lipoidica diabeticorum
erythema nodosum:
-what is this the inflammation of?
-where are the lesions?
-what is the prognosis?
-do they scar?
• Inflammation of subcutaneous fat
• Typically causes tender, erythematous,
nodular lesions
• Usually occurs over shins, may also occur
elsewhere (e.g. Forearms, thighs)
• Usually resolves within 6 weeks
• Lesions heal without scarring
what are different causes of erythema nodosum?
• Infection: streptococci, TB, brucellosis
• Systemic disease: sarcoidosis, inflammatory
bowel disease, Behcet’s
• Malignancy/lymphoma
• Drugs: penicillins, sulphonamides,
combined oral contraceptive pill
• Pregnancy
what are the features of pyoderma gangrenosum:
-where are these?
-how does this develop?
-assoc. symptoms?
• Typically on the lower limbs
• Initially small red papule
• Later deep, red, necrotic ulcers with a violaceous border
• May be accompanied systemic systems e.g. Fever, myalgia
long list of causes of pyoderma gangrenosum:
-name a few
• Idiopathic in 50%
• IBD: ulcerative colitis, crohn’s
• Rheumatoid arthritis, SLE
• Myeloproliferative disorders
• Lymphoma, myeloid leukemias
• Monoclonal gammopathy (IgA)
• Primary biliary cirrhosis
what is the management of pyoderma gangrenosum?
• The potential for rapid progression is high in most patients and whilst topical and intralesional steroids have a role in management most doctors advocate oral steroids as first-line treatment
• Other immunosuppressive therapy, for example Cyclosporin and infliximab, have a role in
difficult cases
what is seborrhoeic dermatitis?
-what is this caused by?
-is this common and what patients are commonly affected?
Seborrhoeic dermatitis in adults is a chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia (formerly known as Pityrosporum ovale). It is common, affecting around 2% of the general population. Seborrhoeic dermatitis is more common in patients with Parkinson’s disease
describe common features of seborrhoeic dermatitis
• Eczematous lesions on the sebum-rich areas: scalp (may cause dandruff), periorbital, auricular and nasolabial folds
• Otitis externa and blepharitis may develop
what are two assoc. conditions with seborrhoeic dermatitis?
Associated conditions include
• HIV
• Parkinson’s disease
what is the management for scalp disease in seborrhoeic dermatitis?
• Over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) are first-line
• The preferred second-line agent is ketoconazole
• Selenium sulphide and topical corticosteroid may also be useful
what is the management for face and body disease in seborrheoic dermatitis?
Face and body management
• Topical antifungals: e.g. Ketoconazole
• Topical steroids: best used for short periods
• Difficult to treat - recurrences are common
where is venous ulceration typically seen?
Venous Ulceration is typically seen above the medial malleolus
what are the investigations for venous ulceration?
Investigations
• Ankle-brachial pressure index (ABPI) is important in non-healing ulcers to assess for poor arterial flow which could impair healing
• A ‘normal’ ABPI may be regarded as between 0.9 - 1.2. Values below 0.9 indicate arterial disease. Interestingly, values above 1.3 may also indicate arterial disease, in the form of false- negative results secondary to arterial calcification (e.g. In diabetics)
what is the management for venous ulceration?
• Compression bandaging, usually four layer (only treatment shown to be of real benefit)
• Oral pentoxifylline (Trental®), a peripheral vasodilator, improves healing rate
• Small evidence base supporting use of flavinoids
• Little evidence to suggest benefit from hydrocolloid dressings, topical growth factors,
ultrasound therapy and intermittent pneumatic compression
what is the most important factor in determining prognosis in malignant melanoma
Malignant Melanoma: the invasion depth of a tumour (Breslow depth) is the single most important factor in determining prognosis of patients with malignant melanoma
What is the approx 5 year survival for malignant melanoma with a breslow thickness of:
< 1 mm -
1 - 2 mm -
2.1 - 4 mm -
> 4 mm -
< 1 mm - 95-100%
1 - 2 mm - 80-95%
2.1 - 4 mm - 60-75%
> 4 mm - 50%
describe the general treatment of impetigo
Impetigo - topical fusidic acid → oral flucloxacillin / topical mupirocin
what is the treatment of impetigo and Limited, localised disease
• Topical fusidic acid is first-line
• Topical retapamulin is used 2nd-line if
fusidin is ineffective or not tolerated
• MRSA is not susceptible to either fusidic acid or retapamulin. Topical mupirocin (Bactroban) should be used in this
situation
what is the treatment of extensive disease in impetigo?
Extensive disease
• Oral flucloxacillin
• Oral erythromycin if penicillin allergic
what is erythema ab igne?
-what can this develop into?
Erythema ab igne is a skin disorder caused by over exposure to infrared radiation. Characteristic features include erythematous patches with hyperpigmentation and telangiectasia. A typical history would be an elderly women who always sits next to an open fire (ovens)
If the cause is not treated then patients may go on to develop squamous cell skin cancer
what is actinic keratoses and what does this develop as a consequence of?
Actinic keratoses, or solar, keratoses (AK) is a common premalignant skin lesion that develops as a consequence of chronic sun exposure
what are the features of actinic keratoses?
• Small, crusty or scaly, lesions
• May be pink, red, brown or the same color as the skin
• Typically on sun-exposed areas e.g. Temples of head
• Multiple lesions may be present
what are different management options of actinic keratoses?
Management options include
• Prevention of further risk: e.g. Sun avoidance, sun cream
• Fluorouracil cream: typically a 2 to 3 week course. The skin will become red and inflamed -
sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation
• Topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
• Topical imiquimod: trials have shown good efficacy
• Cryotherapy
• Curettage and cauter
what is Necrobiosis lipoidica? what condition is this assoc. with?
Necrobiosis lipoidica
o Shiny, painless areas of yellow/red/brown skin typically on the shin o Often associated with surrounding telangiectasia
Diabetes mellitus
what is granuloma annulare?
what is this assoc. with?
• Granuloma annulare*
o Papular lesions that are often slightly hyperpigmented and depressed centrally
*it is not clear from recent studies if there is actually a significant association between diabetes mellitus
and granuloma annulare, but it is often listed in major textbooks
• Infection
o Candidiasis
o Staphylococcal • Neuropathic ulcers
• Vitiligo
• Lipoatrophy
are all assoc with…
diabetes
what is lichen planus?
Planus: Purple, Pruritic, Papular, Polygonal rash on flexor surfaces. Wickham’s striae over
surface. Oral involvement common
what is lichen sclerosus?
Sclerosus: itchy white spots typically seen on the vulva of elderly women
what is lichen planus most likely caused by?
Is a skin disorder of unknown etiology; most probably being immune mediated
describe the features of lichen planus
• Itchy, papular rash most common on the
palms, soles, genitalia and flexor surfaces
of arms
• Rash often polygonal in shape, ‘white-lace’
pattern on the surface (wickham’s striae)
• Koebner phenomenon seen
• Mucous membrane involvement
• Nails: thinning of nail plate, longitudinal
ridging
what 3 different drugs can causes lichenoid drug eruptions?
Lichenoid drug eruptions - causes:
• Gold
• Quinine
• Thiazides
what is lichen sclerosus caused by?
Was previously termed lichen sclerosus et atrophicus. It is an inflammatory condition which usually affects the genitalia and is more common in elderly ♀s. Lichen sclerosus leads to atrophy of the epidermis with white plaques forming
what are the features of lichen sclerosus
-what investigation may need to be performed
Features
• Itch is prominent
A biopsy is often performed to exclude other diagnoses
what is the management of lichen sclerosus?
Management
• Topical steroids and emollients
• ↑ risk of vulval cancer
what is scabies caused by?
Scabies is caused by the mite Sarcoptes scabiei and is spread by prolonged skin contact. It typically affects children and young adults.
what is the pathophysiology of scabies?
The scabies mite burrows into the skin, laying its eggs in the stratum corneum. The intense pruritus associated with scabies is due to a delayed type IV hypersensitivity reaction to mites/eggs which occurs about 30 days after the initial infection.
what are the features of scabies?
Features
• Widespread pruritus
• Linear burrows on the side of fingers, interdigital webs and flexor
aspects of the wrist
• In infants the face and scalp may also be affected
• Secondary features are seen due to scratching: excoriation, infection
what is the management of scabies?
Management
• Permethrin 5% is first-line
• Malathion 0.5% is second-line
• Give appropriate guidance on use
• Pruritus persists for up to 4-6 weeks post eradication
what is appropriate patient guidance on the treatment of scabies?
• Avoid close physical contact with others until treatment is complete
• All household and close physical contacts should be treated at the same time, even if
asymptomatic
• Launder, iron or tumble dry clothing, bedding, towels, etc., on the first day of treatment to kill
off mites.
how is insecticide used in scabies?
• Apply the insecticide cream or liquid to cool, dry skin
• Pay close attention to areas between fingers and toes, under nails, armpit area, creases of the
skin such as at the wrist and elbow
• Allow to dry and leave on the skin for 8–12 hours for permethrin, or for 24 hours for malathion,
before washing off
• Reapply if insecticide is removed during the treatment period, e.g. If wash hands, change
nappy, etc
• Repeat treatment 7 days later
what is type 1 vs type 2 psoriasis?
-age of presentation
-family history
-HLA assoc.
Type 1
• Presents < 40 years old
• Positive family history
• Associated with HLA-CW6
Type 2
• Presents > 50 years old
• No family history
what are the features of psoriasis?
• Red, scaly plaques
• Scalp, extensor surfaces elbows/knees, sacrum
• Nail signs: pitting, onycholysis
• Arthritis
what is the pathophysiology of psoriasis?
• Abnormal T cell activity stimulates keratinocyte proliferation (rather than an actual primary keratinocyte disorder)
• Mediated by type 1 helper T cells
describe 6 topical treatments in psoriasis?
• Simple emollients
• Coal tar: probably inhibit DNA synthesis
• Topical corticosteroids: particularly flexural disease.
Mild steroids are useful in facial psoriasis
• Calcipotriol: vitamin D analogue which ↓ epidermal
proliferation and restores a normal horny layer
• Dithranol: inhibits DNA synthesis, wash off after 30
mins, SE: burning, staining
what is the management of flexural psoriasis?
Flexural psoriasis
• emollients
• topical steroids
Describe phototherapy used in psoriasis?
-what are the adverse effect?
• Narrow band ultraviolet B light (311-313nm) is now
the treatment of choice
• Photochemotherapy is also used - psoralen +
ultraviolet A light (PUVA)
• Adverse effects: skin ageing, squamous cell cancer
(not melanoma)
what is the treatment of scalp psoriasis?
• Calcipotriol lotion
• Steroid lotion + shampoo
• Combination shampoo:
betamethasone with vitamin D
analogues
• Coconut oil compound
shampoos (combination of coal
tar, salicylic acid and sulphur) • Tar shampoo
what systemic therapy can be used in psoriasis?
• Methotrexate: useful if associated joint disease
• Biological agents: infliximab, etanercept and adalimumab, Ustekinumab (IL-12 and IL-23
blocker) is showing promise in early trials.
• Cyclosporin
• Systemic retinoids
who is guttate psoriasis common in? what may precipitate this?
Guttate psoriasis is more common in children and adolescents. It may be precipitated by a streptococcal infection (tonsillitis) 2-4 weeks prior to the lesions appearing
what are the features of guttate psoriasis?
Features
• Tear drop papules on the trunk and limbs
what is the management of guttate psoriasis?
Management
• Most cases resolve spontaneously within 2-3 months
• There is no firm evidence to support the use of antibiotics to eradicate streptococcal infection
• Topical agents as per psoriasis
• UVB phototherapy
• Tonsillectomy may be necessary with recurrent episodes
what is toxic epidermal necrolysis?
-when is this most commonly seen?
Toxic Epidermal Necrolysis (TEN) A potentially life-threatening skin disorder that is mostly seen secondary to a drug reaction. In this condition the skin develops a scalded appearance over an extensive area. Some authors consider TEN to be the severe end of a spectrum of skin disorders which includes erythema multiforme and Stevens- Johnson syndrome
what are the features of TEN?
Features
• Systemically unwell e.g. Pyrexia, tachycardic
• Positive Nikolsky’s sign: the epidermis
separates with mild lateral pressure
what is the management of TEN
• Stop precipitating factor
• Supportive care, often in intensive care unit
• Intravenous immunoglobulin has been shown
to be effective and is now commonly used
first-line
• Other treatment options include:
immunosuppressive agents (Cyclosporin and cyclophosphamide), plasmapheresis
Phenytoin
Sulphonamides
Allopurinol
Penicillins
Carbamazepine
NSAIDs
are all assoc. with…
TEN
what is a keloid scar?
Keloid scars are tumour-like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wound