Dermatology Flashcards
What is Erythroderma?
What is it caused by?
How is it managed?
Inflammatory skin condition covering >90% of the body’s surface.
Eczema, psoriasis, lymphoma, medications, etc.
Admit to hospital as this is an emergency: fluids, manage body temp, check for infection, may use bland topicals/emollients.
Staphylococcal scalded skin syndrome is caused by what underlying mechanism?
Group II staph release toxins which target specific molecules in the body. These are excreted renally and so there is higher risk in those with kidney disease.
Staphylococcal scalded skin syndrome management?
Antibiotics and supportive care.
What is TEN?
Toxic epidermal necrolysis - full thickness epidermal loss most commonly caused by drugs.
Eczema Herpeticum is caused by what?
H.simplex infection of eczema.
Red, scaly, well demarcated, symmetrical patches on the elbows, knees, sacrum, and scalp is what?
Psoriasis
Which medications are associated with worsening psoriasis?
NSAIDS, ACEIs, lithium carbonate, anti-malarial, bet-blockers.
What can happen to the nails in someone with psoriasis?
Pitting
What is Auspitz Sign?
Scratching scales away shows prominent bleeding points.
Indicates vascularity of psoriasis.
Which comorbidities are associated with psoriasis?
Iritis, uveitis, IBD, nail psoriasis, psoriatic arthritis, metabolic syndromes, and psychosocial disability.
How is psoriasis managed?
1st line: Topical corticosteroids, vitamin D or vit D analogies (calcipotriol).
2nd line: dithranol/tar therapy.
3rd line: systemic therapy (methotrexate) and biologics (infliximab).
Management of atopic dermatitis?
1st Line: emollients, topical corticosteroids, calcineurin inhibitors, antiseptics
2nd Line: antibiotics, systemic prednisolone, phototherapy
3rd Line: methotrexate, azathioprine
A wheel-like rash causing intense itching and angioedema is what?
Urticaria
Painful, reddish, erythematous rash occurring most commonly on the anterior shins, associated with IBD is what?
Erythema nodosum - inflammation of subcutaneous fat.
What is the difference between pemphigus vulgaris and bullous pemphigoid?
PV: blistering of skin (blisters are flaccid) in, most common in middle aged adults.
BP: blistering of skin (blisters are tense so burst easily), most common in the elderly.
What is the difference between lichen planus and lichen sclerosis?
LP: pruritic purple papules and plaques found around hair, skin, mouth, and genitals.
LS: itchy, painful white sclerotic patches usually in the genitals.
What is scleroderma?
Autoimmune condition affecting connective tissue, causing hardening and thickening of skin.
Facial redness and telangiectasia worsened by exposure to the sun, most commonly found in elderly is what?
Acne Rosacea.
How is acne rosacea managed?
Topical ivermectin (CI in pregnant or breastfeeding women), topical metronidazole, of azelaic acid 15%.
What is Erythema multiforme?
Target lesions (dark centre surrounded with a pale ring and an outer erythematous ring).
Caused by IgM complexes which become deposited within the skin.
What most commonly causes erythema multiforme? What are other triggers?
1) HSV
Others) mycoplasma, fungal infections, NSAIDs, statins, anti-seizure medications, certain abx, and vaccines.
Pink/red, non-purpuric rash with raised sharper edges and diffuse centre giving a ring like appearance, associated with rheumatic fever is what?
Erythema marginatum
A patient with a ‘plucked chicken’ appearance and angioid streaks on retinal exam is likely what?
Pseudoxanthoma elasticum - autosomal dominant condition causing mineralisation and calcification of elastin fibres throughout the body.
Pyoderma gangrenosum may present with what? What other autoimmune diseases is it associated with?
Ulcerating, intense, dermal infiltration with purulent look (but sterile).
Associated with IBD and RA.
Dermatomal eruption of erythematous papules is likely what? How can it be managed?
Shingles.
Can give acyclovir orals if within 72 hours of sx onset.
What is 1st line for Acne Vulgaris?
topicals: benzoyl peroxide, retinoids, and antibiotics.
A systemically unwell patient with erythema and swelling of the lower leg is likely what?
Cellulitis
How is cellulitis managed?
High dose oral flucloxacillin (clarithromycin/doxy if penicillin allergic, erythromycin if pregnant)
What system scores cellulitis?
Eron score (1-4)
Tinea pedis is also known as what? how is it managed.
Athletes foot - start antifungals and continue until 7 days after erythema has cleared.
How is scabies managed?
Manage with permethrin 5%
Pink nodules with a central herniation, caused by pox virus is what?
Molloscum contagiosum.
What is fish tank granuloma?
Mycobacterium marinum enters through skin lesion causing slow growing inflamed nodule/plaque at trauma site.
Golden, crusting lesions most commonly caused by staph but also caused by strep is what?
Impetigo.
How is impetigo managed?
Localised - Hydrogen peroxide cream 1%
Widespread- Fusidic acid 2%, or oral fluclox (clari if pen allergic, erythro if pregnant) for 5 days.
Bullous/systemically unwell - 7 days or orals as above.
What is an exanthem?
Any widespread, uncomfortable rash, accompanied by systemic features, that blanch under pressure.
What is pityriasis vesicolor?
Brown, scaly macules often on the trunk that do not tan in the sun. Caused by tinea vesicolor fungus.
What is Pityriasis Rosea?
Begins as a large, circular or oval, ‘herald patch’ which is often raised and scaly.
Followed by a widespread rash (2 days after).
It is a form of herpes infection.
Pox virus transmitted from sheep/goats is known as what?
Orf.
What is the most common cause of dermatophyte toe nail disease?
Trichophyton rubrum
How is a dermophyte nail infection managed?
If amorolfine lacquer (can be bouth OTC) is unsuccessful then use 3-6 months of oral terbinafine.
What causes erysipelas in adults and newborns?
Adults - group A beta-haemolytic strep (strep pyogenes).
Newborns: streptococcus agalactiae
How does erysipelas present? What is it?
Rash on the face that feels hot and swollen to the touch, associated with malaise, and feeling generally unwell.
Infection of the dermis and upper subcutaneous tissue (whereas cellulitis is entire SC layer this is just the superficial part)
Cafe-au-lait macules are suggestive of what?
Neurofibromatosis.
What is porphyria cutanea tarda?
Build up of porphyrin precursors in response to sunlight causing mila (white/yellow bumbs), skin fragility, hypertrichosis and blistering.
Due to abnormality of haem biosynthesis.
What is chronic actinic dermatitis?
Photosensitive eczema
What is the Koebner phenomenon?
Formation of new lesions (eczema, psoriasis, etc) at the site of trauma after injuries.
What is the Nikolsky sign?
Application of tangential mechanical pressure to erythematous zones produces detachment of the epidermis from the dermis.
Associated with SJS and TEN.
What is Steven-Johnson Syndrome? Mx?
Symptoms resembling an URTI followed erythematous macules and mucosal ulceration affecting <10% of the body surface.
Management is supportive.
Associated with medications and various infections.
What are the systemic long term side effects of corticosteroids?
Mineralocorticoids: HeTN, Na and water retention, K loss.
Glucocorticoids: osteoporosis, diabetes, cushings, peptic ulcer disease, neuropsychiatric problems, increased risk of CVD.
How does azathioprine work?
What breaks it down in the body and what implications does this have clinically?
Steroid sparing agent, works against lymphocytes.
Broken down by TPMT so need o check pt has enough to break it down before prescribing.
SEs of methotrexate?
Mutagenic (CI in men and women planning conception)
Bone marrow toxicity
Hepatotoxicity
Lung Fibrosis
How does cyclosporine work? Is it safe in pregnancy? Long-term SEs?
Works against T cells.
Yes.
5 Hs’s: hypertrichosis, hypertrophy of gums, hypertension, hyperkalaemia, hyperglycaemia, AND SCC
What are the potential SEs of retinoids?
teratogenicity, hyperlipidaemia, hepatotoxicity, skeletal abnormalities.
What is the Leser-Trelat sign?
Sudden eruption of seborrheic keratoses associated with malignancies (especially colorectal adenoma)
What is the weighted 7 point checklist for referring a lesion from GP to secondary care?
2 points for: change in size, irregular shape, irregular colour,
1 point for: >7mm, inflammation, oozing, change in sensation
>3 points = refer
Scaly, rough patches, usually on a background of red which may be thick and wart like, associated with sun exposure is what? How is it managed?
Actinic/solar keratoses.
Topical 5-fluorouracil is 1st line.
What is Bowen’s Disease?
Early stages of SCC, typically on lower legs, hands, nails. Usually fixed, slightly scaly (but don’t respond to moisturisers), erythematous patches of skin.
Shiny, pearly nodules, with irregular vessels often appearing as a red patch is likely what? How is it managed?
BCC.
High risk should be excised, lower risk can try topical treatments.
Warty (keratin producing) tumours on a fleshy base, sometimes associated with ulceration is likely what?
SCC.
What is a Keratoacanthoma?
Variant of SCC, rapid growing hard keratin plug which often resolves leaving a depressed scar. Managed the same as SCC as hard to differentiate.
What is Mycosis Fungoides?
T-cell lymphoma of the skin causing scaly, erythematous, atrophic skin, may be dyspigmented and may be associated with alopecia.
A melanoma in the younger population which presents as an irregular lesion in both shape and colour which is progressively changing is what type?
Superficial spreading melanoma
A melanoma in the younger population presenting as palpable raised nodules above the skin with subtle pigmentation with vascularity is what type?
Nodular melanoma.
A melanoma in the older population which is slow growing and may look like a freckle is what type?
Lentigo maligna melanoma
A melanoma in the older population found on soles and nails is what?
Acral lentiginous melanoma
What is the management of dermatitis herpetiformis?
Dapsone
What are the components of Staphylococcal toxic shock syndrome?
- Fever >38.9
- Rash with diffuse macular erythroderma
- Desquamation 1-2 weeks after - rash onset
- Systolic BP <90
- Multi-organ involvement (GI, renal, hepatic, thrombocytopenia, neuro)
What is 1st line for Lichen Planus?
Topical corticosteroids.
What antibodies are associated with bullous pemphigoid? What are common drug triggers?
- Antibodies against hemidesmosome proteins BP180 and BP230.
- Spironolactone, furosemide, sulfasalazine, Penicillins, beta-blockers, antipsychotics, enoxaparin,
What fungus causes pityriasis versicolor? Who is it often seen in?
Malassezia furfur fungus,
Seen in young adults in humid climates or those that heavily perspire.
What Breslow thickness indicates the need for a sentinel node biopsy?
> 1mm
How do thiazides cause lithium toxicity?
Reduces renal clearance of lithium causing build up.
What is acanthosis nigricans? What does it indicate?
Thickened, velvety, hyperpigmented patches of skin found in skin folds such as axilla and neck folds.
In the young - insulin resistance.
Older populations (>40) - malignancy such as gastric adenocarcinoma).
What is used to manage simple urticaria?
Non-sedating anti-histamines such as cetirizine, loratadine and fexofenadine.
What is first and second line for cutaneous warts?
1) Topical salicylic acid
2) Cryotherapy
