Dermatology Flashcards
1
Q
How long do you leave sutures in?
A
Face 5d
Joints 14d
Rest of the body 7-10d
2
Q
Suture Types and which to use
A
Nonabsorb : Ethiopian, Prolene
Absorb : plain or chromic gut, vicryl
Face use 5-6 nonabsorb
Skin use 4-5 nonabsorb
(3-4 vicryl for deep tissue)
3
Q
Name the animal and human bite pathogens
A
Animal : Pasturella multocida, S Aureus, S Viridans
Human : Eikenella corrodens, Staph, alpha-hem strep, bacteroides
4
Q
Name the animal and human bite pathogens
A
Animal : Pasturella multocida, S Aureus, S Viridans
Human : Eikenella corrodens, Staph, alpha-hem strep, bacteroides
5
Q
Explain the treatment for bite lacerations
A
No suture! Heals by secondary closure
Ensure tetanus prophylaxis
Antibiotics : Clavulin 875 BID or Amox 40mg/kg/d TID
2nd line : Doxy 100BIDx1 (2-4) then 100OD (1-2) or Ceftri 1-2gOD IV/IM (50-10)
Consider rabies for animal bites
6
Q
Explain rabies treatment in animal bites
A
IgG 20u/kg around wound or IM
AND
Vaccine 1.0mL deltoid day 3,7,14,28
7
Q
Lidocaine max dose
A
1% 5mg/kg
8
Q
Which lacerations are more complicated and may require special skills for repair
A
Second versus third-degree perineal tear , lip or eyelid lacerations involving margins, arterial lacerations
9
Q
What kind of lacerations require more than simple sutures
Name some complications
A
Flexor tendon lacerations
open fractures
bites to hands or face
neurovascular injury
foreign bodies
10
Q
List wounds at high risk for infection.
Do you close these?
A
Puncture wounds
Some bites
Some contaminated wounds
Do not suture them
11
Q
Describe the systematic approach to repairing second-degree perineal lacerations
A
- identify the apex of the lac, hymenal ring, perineal muscles, intact anal sphincter
- secure the apex and align the hymen and perineal body, then suture vaginal mucosa from apex to hymen
- Suture perineal muscles
- Suture skin or plan to let heal by 2nd intention
12
Q
Describe the systematic approach to repairing second-degree perineal lacerations
A
- identify the apex of the lac, hymenal ring, perineal muscles, intact anal sphincter
- secure the apex and align the hymen and perineal body, then suture vaginal mucosa from apex to hymen
- Suture perineal muscles
- Suture skin or plan to let heal by 2nd intention
13
Q
Describe the systematic approach to repairing second-degree perineal lacerations
A
- identify the apex of the lac, hymenal ring, perineal muscles, intact anal sphincter
- secure the apex and align the hymen and perineal body, then suture vaginal mucosa from apex to hymen
- Suture perineal muscles
- Suture skin or plan to let heal by 2nd intention
14
Q
Management of Acne
A
- Benzoyl Peroxide 2.5-5%
- Topical retinoids (Adapalene 0.1%)
- Combined BP/Adap (TactuPump) or BP/Clinda (Clindoxyl)
- Clinda 1%/tretinoin 0.025%
- OCP / Spirinolactone 50-200mgOD
- Oral abx : Minocycline 100mg then 50mg > Doxy 100mg > Tetra 500mg then 250-500mg > Erythro same dose
- Isoretinoin / Accutane
ALWAYS USE TOPICALS WITH ORAL ABX, DO NOT USE ORALS FOR >3MO WITHOUT FU
15
Q
Isoretinoin Dosage and Precautions
A
Accutane 0.5mg/kg/d ÷ OD-BID x 4w then 1mg/kg/d x 3-7mo
Prgnancy tests, double contraception, avoid pregnancy 3mo post tx, monitor CBC, LFTs, lipids at 0, 1, +q3mo
16
Q
DDx : Acne (4)
how to differentiate
A
- Rosacea : mostly central face, pustules, flush reaction, telangiectasia
- Perioral dermatitis : only pustules, mostly around the mouth
- Folliculitis : pustules around beard area
- Acneiform erruption : drug reaction
17
Q
Types of acne (5), which to refer*?
A
- Comedones : open or obstructed, little inflammation
- Common/vulgaris : pustules + comedones
- *Cystic : form scars
- *Conglobata : multilobular inflammatory scar-forming cysts
- *Fulminans : systemic sx (fever, arthralgia, skeletal foci of inflammation)
18
Q
Associated features of eczema/atopic dermatitis
A
Atypical vascular responses (facial pallor, white dermographism, delayed blanch response)
Keratosis pilaris, pityriasis alba, hyperlinear palms, ichthyosis
Ocular/periorbital changes
Perifollicular accentuation, lichenification, prurigo lesions
Asthma, hay fever
19
Q
Ddx : eczema/atopic dermatitis
A
Scabies
Seborrheic dermatitis
Cutaneous T-cell lymphoma
Psoriasis
20
Q
Pharmacological tx of eczema
A
- Intermittent topical steroids
- Intermittent tacrolimus 0.03-0.1%(lymphoma risk)
- Pimecrolimus 1% (lymphoma risk)
- Crisaborole 2% BID
- Ruxolitinib cream (black box warning)
- Systemic (phototherapy, methotrexate, cyclosporine, azathioprine)
21
Q
What is tacrolimus ?
A
Tacrolimus, brand name Prograf among others, is an immunosuppressive drug in a class of medications called topical calcineurin inhibitors. It works by stopping the immune system from producing substances that may cause eczema.
22
Q
Provide examples of topical corticotherapies (low to high strength)
A
Low : HC 0.5-2.5% (hyderm, Emo-cort)
Med : Betamethasone (Betaderm) 1%
High : Betamethasone (Diprolene < Diprosone) 0.05% and Clobetasol (Dermovate) 0.05%
23
Q
How many grams of cream/lotion/ointment do you provide for given body areas?
A
Hand : 1g x BID = 15g per week
Face : 2g x BID = 30g
Arm : 3g x BID = 45g
Leg : 4g x BID = 60g
Whole body : 30-60g x BID = 500-1000g
24
Q
Types of dermatitis and their tx
A
- Atopic (eczema) –> steroids, tacrolimus
- Contact –> steroids, tacrolimus
- Dyshidrotic –> high potency HC
- Nummular –> high potency HC
- Seborrheic –> ketoconazole (nizoral), selenium, Zn pyrithione (Head and Shoulders), HC
25
Diagnose and Investigate : Pemphigus
Pemphigus presents with fragile, flaccid blisters on the skin and mucous membranes. It’s serious due to risk of widespread skin involvement, infection, and complications from blisters in mucous membranes.
Direct immunofluorescence microscopy of a skin biopsy showing intercellular IgG deposits between keratinocytes.
26
Name the six main types of psoriasis.
Plaque (vulgaris)*, guttate (strep), inverse, pustular (life threatening), erythroderma (>90% of body, life threatening), annular.
*most common 80%
“Psoriasis Is Always Gonna Evolve Poorly”
27
List some risk factors associated with psoriasis.
Genetic predisposition, stress, obesity, smoking, alcohol use, certain medications (BB, NSAIDs, Li, tetracycline), infections (strep --> guttate), trauma (Koebner phenomenon)
28
How does plaque psoriasis typically present?
Symmetric, well-defined, raised, red plaques with silvery-white scales, often on extensor surfaces such as elbows, knees, and scalp. Usually not itchy, but can be. Can be painful.
29
What percentage of psoriasis patients develop psoriatic arthritis? What kind of arthropathy is it?
Approximately 20-30% of psoriasis patients develop PsA.
Seronegative arthropathy.
30
Types of psoriatic arthritis
Distal / DIP
- asymmetric oligo
- symmetric poly
- arthritis mutilans
- spondyloarthropathy
often develops dactylitis (sausage digit)
31
DDx : psoriasis
Atopic dermatitis
Contact dermatitis
Lichen PLanus
Secondary syphilis
Mycosis fungoides
Tinea corporis
Pityriasis
32
What are the nail changes seen in psoriasis?
Pitting, onycholysis (detachment of the nail), oil-drop sign, and subungual hyperkeratosis.
33
What are first-line topical treatments for mild to moderate psoriasis?
1. Lubricants
1. Corticosteroids (mod to strong)
1. Vitamin D analogs (calcipotriene, calcitriol) : Dovobet (D + betamet) or Dovonez
1. Topical retinoids (tazarotene) Tazorac gel)
1. Coal tar
1. Salicylic acid
1. Anthralin
2. Phototherapy, cyclosporine, MTX, oral retinoid (acitretin)
3. Biologics (Adalimumab, Etanercept, Infliximab)
34
Chicken Pox presentation
Rash from face to trunk to extremities
Papules to vesicles to pustules to crust
Dewdrop on a rose petal
35
Kawasaki Presentation
CRASH
- Bilateral conjunctivitis
- Rash : polymorphous
- ADNP
- Strawberry tongue
- Hands and Feet desquamation
36
Kawasaki Complications
Coronary artery aneurysm, myocarditis, pericarditis, pericardial effusion, valvular dysfunction, LV dysfunction, arrythmia
37
Kawasaki Management
IVIG + high dose ASA (80-100mg/kg/d/QID)
Decr to ASA 3-5mg/kg/d x 6-8weeks after fever (48-72h)
38
Lyme Disease Pathogen and Presentation
Borrelia Burgodorferi
Erythema migrans : red patch / target / bulls eye
39
Measles Presentation
Macular rash from face to shoulders downwards on d4 of fever
The C's : coryza, cough (bark-like), Koplik's spots
Fades in 4-6d, incubation 10-14d, infective 4d pre-rash
40
Parvovirus Names and Presentations and Complication
5ths Disease / Slapped Cheek
Cheeks to lacy reticular rash post fever
Wax + wane x 6wks
Severe aplastic anemia in pts w/ chronic haemolytic anemia
41
Rocky Mountain Spotted Fever Presentation
Abrupt T, HA, myalgias --> rash 4d later : Pink macules to red papules to petechiae on wrists and ankles towards center (palms + soles late in disease)
Possible bradycardie, leukopenia
42
Roseola virus and presentation
HHV-6
Fever x 3-4d --> Rash within 2-3d --> Lasts 2-3d
Diffuse, face-sparing, macular rash
43
Rubella Presentation
Pink macules and papules from forhead downwards within 1d, fades in reverse order
Forchheimer spots**
Infective 7dpre to 5d post rash
Prodrome uncommon in children
Mild URTI, anorexia, malase, HA in adults
44
Scarlet Fever Presentation
Punctuated rash on trunk to extremities, flushed face, perioral pallor, fades in 4-5d, followed desquamation
Clues : 2-3d after strep, Pastia's sign (folds), white to red strawberry tongue
45
Rosacea Presentation
central face with transient or persistent erytehma, telangiectasia, inflammatory papules/pustules, hyperplasia of connective tissues
feeling of warmth
46
DDX : Rosacea
- Acne vulgaris
- Seborrheic dermatitis
- SLE
- Carcinoid syndrome
47
Rosacea subtypes
Erythematotelangiectatic
Papulopustular
Phymatous
Occular
48
Rosacea 1st line treatment
Metronidazole 1% gel or cream
Azelaic acid gel
Brimonidine
49
Rosacea 2nd line treatment
ABx : Doxycycline or Tetracycline
Laser / Light Therapy
Propranolol
50
Rosacea flushing treatments
Propranolol 20-40mg (for flushing)
Carvedilol (BB)
Clonidine (ablocker)
51
Ocular rosacea treatments
Eyelid hygiene / massages / warm compresses / artificial tears
Oral doxycycline or tetracycline
Referral to an ophthalmologist may be necessary in severe cases.
52
Clinical Features of T Cell Lymphoma
**Persistent, patchy, red, scaly skin lesions that do not improve with standard treatments, and can progress to plaques or tumors over time.
Mycosis Fungoides (limited superficial)
- patches --> poikiloderma (thinning and telangiectasia) --> plaques --> tumour stage
Sezary Syndrome
- widespread systemic type, "red man" syndrome, fatigue, fever, often fatal
53
What is the treatment for T Cell Lymphoma types?
Mycosis Fungoides : Topical steroids, PUVA or UVB application
Sezary Syndrome : Oral retinoids and interfereon, extra-corporeal photophoresis, possible radiotherapy
54
Diagnose and Investigate : Cutaneous T-cell lymphoma
Skin biopsy with immunohistochemistry, flow cytometry, or T-cell receptor gene rearrangement studies.
55
Diagnose and Investigate : Melanoma
"ABCDE" criteria (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolution)
+EFG : Elevated, firm, growing (Nodular Melanoma)
56
How do you treat melanoma? What's the prognosis?
Biopsy, typically an excisional or punch biopsy, depending on lesion size and location, to provide histopathological analysis. Avoid shave biopsy. Remove full depth of dermis.
Staging/prognosis = Breslow thickness
57
Differentiate between the non-melanoma skin cancers (NMSC)
BCC : pearly, telangiectasia, on face, slow, local, can treat by excision, radiation or Aldara
SCC : scale/crust, on sun exposed areas, fast, 5-10% metastasize, can treat by excision or radiation
58
What are the characteristic cutaneous findings in systemic lupus erythematosus (SLE)?
What investigations are useful for confirming (SLE)?
Malar (butterfly) rash on the cheeks and nose, photosensitivity, discoid lesions, and oral ulcers.
ANA (antinuclear antibody), anti-dsDNA, anti-Smith antibodies, and complement levels (C3 and C4).
59
How does Wegener’s granulomatosis (now known as Granulomatosis with Polyangiitis) typically present on the skin?
Which lab test is commonly used to help diagnose (GPA)?
Purpura, ulcers, and nodules, often with necrotic centers, due to vasculitis.
c-ANCA (cytoplasmic anti-neutrophil cytoplasmic antibodies), along with biopsy of affected tissues showing granulomatous inflammation.
60
What are common cutaneous signs of a drug reaction?
Rash, urticaria, fixed drug eruptions, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), and drug-induced hypersensitivity syndrome (DRESS).
61
What are cutaneous signs of dermatomyositis, and what systemic disease should be considered?
Which investigations confirm a diagnosis of dermatomyositis?
Heliotrope rash on the eyelids, Gottron's papules on knuckles, and shawl sign. Consider underlying malignancy or interstitial lung disease.
Muscle enzymes (CK, aldolase), EMG, skin/muscle biopsy, and antibody testing (anti-Jo-1, anti-Mi-2).
62
What are the cutaneous manifestations of systemic sclerosis (scleroderma)?
What key investigations help confirm systemic sclerosis?
CREST : Calvinist’s, Raynaud, esophageal dysfunction, sclerodactyle and skin thickening, telangiectasias.
ANA, anti-Scl-70 (anti-topoisomerase I), and anti-centromere antibodies, along with organ-specific tests (e.g., PFTs for lung involvement).
63
What are the skin manifestations of sarcoidosis?
How is sarcoidosis confirmed after observing cutaneous signs?
Erythema nodosum (red, painful nodules on shins) and lupus pernio (violaceous plaques on the nose, cheeks, and ears).
Chest X-ray or CT for pulmonary involvement, serum ACE levels, and biopsy of affected skin or lymph nodes showing non-caseating granulomas.
64
What is DRESS syndrome, and how does it present?
Which investigations are key in diagnosing DRESS syndrome?
What is the management ?
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) presents with fever, widespread rash, facial edema, and lymphadenopathy, often with eosinophilia and liver involvement.
CBC (eosinophilia), liver function tests, and history of recent drug exposure.
Stopping the offending drug is critical +/- corticosteroids
65
What cutaneous signs might indicate vasculitis as a systemic condition?
Palpable purpura, livedo reticularis, ulcers, and nodules, often seen in small-vessel vasculitis.
66
What is Stevens-Johnson Syndrome (SJS), and how does it typically present?
SJS is a severe mucocutaneous reaction characterized by widespread skin detachment, painful erythematous or purpuric macules, and mucosal involvement, often triggered by medications.
67
How is SJS distinguished from Toxic Epidermal Necrolysis (TEN)?
SJS involves <10% body surface area (BSA) detachment, while TEN involves >30% BSA detachment. Between 10–30% BSA is classified as SJS/TEN overlap.
68
What is the initial management of Stevens-Johnson Syndrome (SJS)?
Stop the offending drug, initiate supportive care (fluids, pain management), transfer to a burn unit if extensive, and consider systemic steroids or IV immunoglobulin in severe cases.
69
What is the primary bacterial cause of invasive cellulitis?
Group A Streptococcus and Staphylococcus aureus, including MRSA, are common causes of invasive cellulitis.
70
What are key signs of invasive cellulitis?
Rapidly spreading erythema, warmth, tenderness, swelling, fever, and systemic symptoms. Can progress to necrotizing fasciitis if untreated.
71
What is the initial treatment for invasive cellulitis?
Empirical IV antibiotics targeting Streptococcus and Staphylococcus (e.g., cefazolin or clindamycin), followed by wound assessment and debridement if needed.
72
How does necrotizing fasciitis differ from cellulitis, and what is its hallmark sign?
Necrotizing fasciitis is a rapidly progressive infection of the fascia with severe pain, often disproportionate to physical findings, and can include crepitus and skin necrosis.
73
What is the urgent treatment for necrotizing fasciitis?
Immediate surgical debridement, broad-spectrum IV antibiotics (e.g., piperacillin-tazobactam with vancomycin), and supportive care in an ICU setting.
74
What are common causes of chemical burns?
Acids (e.g., hydrochloric acid), alkalis (e.g., lye), and other irritants, with alkalis causing deeper and more severe tissue damage.
75
What is the first step in treating a chemical burn?
Immediately irrigate with copious amounts of water (at least 20–30 minutes), remove contaminated clothing, and avoid neutralizing agents, which can worsen the burn.
76
What are signs of severe thermal burns that require emergency intervention?
Burns involving >10% BSA in adults, >5% in children, or any burn involving the face, hands, feet, genitals, or respiratory tract.
77
What are the symptoms of toxic shock syndrome (TSS), what pathogens are responsible? What abx do you give?
Sudden high fever, diffuse rash resembling sunburn, hypotension, and multiorgan involvement, often linked to Staphylococcus aureus or Streptococcus infections.
Start with Clindamycin plus Vanco
**In prophylaxis, you can give clavulin
78
What is erythema multiforme? What is the treatment?
Erythema multiforme major typically presents with target lesions and minimal mucosal involvement, often linked to infections.
Treat underlying infection (e.g., HSV with antivirals), supportive care for skin lesions, and hospitalization if severe.
79
What is the pharmacotherapy of candidiasis for thrush, skin, vs vulvovaginal?
Thrush : nystatin
Skin : nystatin
Vulvovaginal : Clotrimazole 200mg PV x 3d or 2% x 3d, Miconazole 400mg or 4% x 3d, or Fluconazole 150mg PO x1
**if >4 episodes per year : fluconazole 150mg PO q3dx3 doses or topical azole x 10-14d THEN Fluconzaole 150mg PO q1wk x 3-6 MONTHS
80
What is the pharmacotherapy of tinea corporus? Tinea pedis?
Ketoconazole cream or oral for 10d
Pedis : terbinafine 1% 1-4w or azoles (clotrimazole 1% 4-6w), tea tree oils, foot hygiene **oral ony in severe / tx failure / immunocompromised cases
81
How do you treat onychomycosis?
Efinaconazole +/- Terbinafine
Oral terbinafine if >60% involvement
**lab test before treatment
82
What is the etiology of Impetigo? The clinical features? What is the pharmacotherapy?
Group A Strep or S. Aureus
Vesciles --> golden, honey crusted lesions
Topical 5-7d > oral abx 7-10d
Mupirocin 2% TID, Fusidic acid 2% TID-QID or Ozenoxacin 1% BID
Cephalexin 50-100mg/kg/d QID (max 250-500mg QID) or Cloxacillin 50mg/kg/d QID (max 250-500) or Clinda or Doxy
**If MRSA risk : swab and tx w/ Septra or Doxy
83
What is a risk of lice? What is the pharmacotherapy?
Secondary bacterial infection
Pyrethrins <2mo day 1 and repeat day 10
Permethrin >2mo and repeat day 7
84
What kind of infection is scabies? What is the pharmacotherapy?
Parasitic, transmitted skin to skin, itching begins 1mo after incubation and can last 2-3wks post tx
Permethrin 5% day 1 x 12h and repeat day 7
