Derm Flashcards
Mild acne treatment
Benzoyl peroxide and salicylic acid cleansing
Topical retinoids for comedones (Tretinoin, Adapalene/Differin)
Antimicrobials (clindamycin, erythromycin)
Moderate acne treatment
Oral abx for max 12 weeks (tetracycline/minocycline/doxycycline)
Hormones (OCP)
Spironolactone (Aldactone)
Severe acne treatment
Isotretinoin (accutane, clarus, epuris)
Monotherapy
*Make sure pt is not pregnant
**Pt should be on 2 forms of birth control while on isotretinoin
Alopecia areata
AI dz: T cell lymphocytes cluster around germinative zones of hair follicles –> inflammation –> hair loss
Hair follicles still alive
Alopecia areata tx
Topical minoxidil = vasodilator
Topical anthralin
Cortisone or triamcinilone actonide injections
Oral steroid
Contact dermatitis tx
If >20% affected –> oral prenisone
Topical corticosteroids = first line for localized allergic contact dermatitis (topical triamcinolone)
Bulla
Fluid-filled blister >0.5cm in diameter
Vesicle
Fluid-filled blister <0.5cm indiameter
Furuncle
Purulent infected hair follicle
Pustule
Visible collection of pus in skin <1cm in diameter
Abscess
Localized collection of pus in a cavity >1cm in diameter
Nodule
Circumscribed palpable mass >0.5cm diameter
Plaque
Flat topped palpable mass which is >1cm in diameter
Macule
Circumscribed area of altered skin colour without elevation <1cm in diameter
Patch
Circumscribed area of altered skin colour without elevation >1cm in diameter
Telengiectasia
Visible dilatation of small cutaneous blood vessels
Petechia
Purpuric lesion of 2mm or less in diameter
Ecchymosis
Large purpuric lesion
Most common causes of erythematous perianal rashes in neonates
Irritant diaper dermatitis
Seborrheic dermatitis
Candida diaper dermatitis
Carbuncle
Painful cluster of boils
Melanoma dx
Excisional bx
Try to take it all if possible but if not take darkest portion
Melanoma tx
Wide excision with adequate margins
Sentinel LN biopsy
Systemic therapy if stage III or IV
Adequate margins for melanoma
In situ –> 0.5cm margins
= 1 mm –> 1cm margins
1.01 - 2mm –> 1-2 cm margins
>2.01 mm –> usually 2cm margin
Acute urticaria time frame
<6wks
Chronic urticaria time frame
> /= 6 wks
Primary inflammatory cells of urticaria
Mast cells and basophils
Usual medications that can cause urticaria
Antibiotics (penicillins, cephalosporins), NSAIDs
Most common cause of chronic urticaria
Dermatographism
Bullous pemphigoid
Most common AI subepidermal blistering disorder
Common in elderly pt >60yo
Tx: Superpotent topical steroid or immunomodulators, if systemic required - tetracycline abx, systemic corticosteroid, azathioprine, MTX, mycophenolate
Scabies tx
Permithrin 5% from neck down with 2 treatments spaced 1 wk apart
Acute Urticaria tx
1st line: antihistamines (diphenhydramine, hydroxyzine, cetirizine)
Chronic urticaria tx
ANtihistamines (2nd generation as first line - ie. cetirizine, desloratadine, loratadine) 1 pill daily for at least a week
2nd line: omalizumab
3rd line: cyclosporin, montelukast, MTX
Avoid systemic steroids if you can
Corns vs warts vs calluses
Corns are painful with direct pressure, interrupt dermatoglyphics
Warts bleed with paring, black speckled apperance due to thrombosed capillaries, destory dermatoglyphics
Calluses have layers, no thrombosed capillaries or interruption of epidermal ridges
Corn treatment
Relieve pressure in shoes
Topical salicylic acid
Junctional nevus
Flat, regular borders, demarcated
Tan-dark brown
Form from melanocytes at dermal-epidermal junction
Compound nevus
Often formed from junctional Tan-dark brown Domed, regularly bordered, smooth, round NOT on palms or soles Form from melanocytes at dermal-epidermal junction that migrate into dermis
Dermal nervus
Soft, dome-shaped, skin coloured to tan/browm
Form from melanocytes exclusively in dermis
Perioral dermatitis tx
AVOID all topical steroids
Topical metronidazole 0.75% gel or 0.75-1% cream to affected area BID
Systemic tetracyline abx
Rosacea tx 1st line
Oral tetracyclines Topical metronidazole Oral erythromycin Topical azelaic acid Topical ivermectin AVOID topical steroids Avoid triggers
Tacrolimus and Pimecrolimus are types of…
Topical calcineurin inhibitors
Good for steroid-sparing agent
Can be used on face and neck
Seborrheic dermatitis tx
Possibly associated with Malassezia (yeast)
Ketonozaole or mold steroid to face
Salicylic acid in olive oil or derma-smoothe lotion to remove scales on scalp, ketoconazole shampoo, head and shoulders (zinc pyrithione), steroid lotion (betamethasone)
6Ps of Lichen planus
Purple Pruritic Polygonal Peripheral Papules Penis (60% in mouth, vulva, glans - mucous membranes)
Pathognomonic sign of lichen planus
Wickham’s striae (white/grey lines over surface)
Pityriasis rosea
Christmas tree pattern on back
Herald patch preceding other lesions by 1-2wks
Suspected caused by HHV-6 or HHV-7 reactivation
No tx required
Clears spontaneously in 6-12wk
Psoriasis tx
Topical steroids +/- topical vitamin D3 analogues (ie.Calcipotriol/Dovobet)
If severe, consider UVB or PUVA phototherapy or systemic biologic therapy
Guttate psoriasis often caused by…
Streptococcal pharyngitis
Pemphigus vulgaris vs bullous pemphigoid
VulgariS = Superficial, intraepidermal, flaccid lesions PemphigoiD = Deeper, tense lesions at dermal, epidermal junction
Nibolsky’s sign
Epidermal detachment with shear stress
Asboe-Hansen sign
Pressure applied to bulla causes it to extend laterally
Pemphigus vulgaris
AI blistering disease most commonly in mouth
IgG against epidermal desmoglein -1 and -3 leading to loss of intracellular adhesion in epidermis
Tx: Prednisone +/- steroid sparing agents (ie. azathioprine, cyclophosphamide, cyclopsorine)
Celiac disease often a/w this skin condition
Dermatitis Herpetiformis
Dermatitis herpetiformis
Transglutaminase IgA deposits in skin alone or in immune complexes leading to eosinophil and neutrophil infiltration
Grouped papules/vesicles/urticarai on erythematous base
Tx: Dapsone, gluten free diet for life (reduce risk of lymphoma)
Common causative agents for exanthematous drug reaction
Penicillin
Sulfonamides
Phenytoin
Drug reaction with Eosinophilia and Systemic Symptoms (DRESS)
Starts with face or periorbitally and spreads caudally
No mucosal involvement
Onset 1-6wk after first exposure to drug
Persists wks after withdrawal of drug
Common culprits: Anticonvulsants, allopurinol, sulfonamides
Tx: D/C drug, prednisone, consider cyclosporine in severe cases
Steven Johnson Syndrome
Epidermal detachment BSA <10%
Toxic epidermal Necrolysis
Epidermal detachment BSA >30%
Gene a/w SJS/TENS with carbamazepine
HLA-B1502
Gene a/w SJS/TENS with allopurinol
HLA-B5801
Common causative agents for SJS/TENS
Anticonvulsants Sulfonamides Allopurinol NSAIDs Cephalosporins Can also be caused by viral or mycoplasma infections
Neurofibromatosis inheritance pattern
Autosomal dominant
AI diseases linked to vitiligo
Thyroid
Pernicious anemia
Addison’s disease
Type I DM
Treatment of vitiligo
Sun avoidance
Topical calcineurin inhibitor or topical corticosteroids
PUVA or NB-UVB
Impetigo cause
GAS, S. aureus or both
Tx of Impetigo
Topical antibacterials (2% mupirocin or fusidic acid TID for 7-10d only) Systemic abx (ie. cloxacillin or cephalexin for 7-10d)
Erysipelas tx
1st line = Penicillin, cloxacillin or cefazolin
2nd line = clindamycin or cephalexin
Common tx for DM foot infections
TMP/SMX and metronidazole
Tinea capitis tx
Terbinafine PO x 4wk
Oral agents required to penetrate hair root where dermatophyte resides
Adjunctive antifungal shampoos or lotions may be helpful
Onychomychosis tx
Terbinafine or Intraconazole PO 6wk for fingernails, 12wk for toenails for SEVERE onychomycosis (Itraconazole should not be used with statins, terbinafine should not be used with SSRI)
Mild to moderate: topical efinaconazole
Lice tx
Permethrin 1%, repeat in 1wk after tx
HSV-1
Typically cold sores
Tx during prodrome to prevent vesicle formation
Topical antiviral cream, oral antivirals are more effective
HSV-2
Usually sexually transmitted
1st episode: Acyclovir 200mg PO 5x/d x 10d, maintenance acyclovir 400mg PO BID
HSV smear
Tzanck smear
Hutchinson’s sign
Shingles on tip of nose signifies ocular involvement
Shingles in this area involves V1 (ophthalmic branch of trigeminal nerve)
Mollascum contagiosum tx
Topical cantharidin
Candidal paronychia tx
Oral antifungals recommended
Topical therapies for actinic keratosis
5-fluorouracil cream for 2-4wks
Imiquimod
Most common oral mucosal premalignant lesion
Leukoplakia
Basal cell carcinoma
Rarely metastatic
Most common malignancy
Tx: Imiquimoid 5% cream, cryotherapy, fluorouracil, photodynamic t herapy for superficial
Shave excision, electrodessication for most types of BCCs
LOCAL excision (<1cm margin, wide excision not necessary)
Mohs surgery
Squamous cell carcinoma tx
Surgical excision with primary closure, Mohs
Lifelong follow-up
+/- radiation (higher rates of mets if >2cm in diameter, >4mm deep)
Melanoma treatment
Excision (full depth of dermis) + margins AFTER histologic dx
High dose IFN for stage II
Chemotherapy and high dose IFN for stage III
Node dissection if Stage IB or higher (if 0.8mm or thicker)
Increased rate of mets in melanoma
Growth stage of hair growth
Anagen phase
Transitional stage of hair growth
Catagen stage
Resting stage of hair growth
Telogen phase
Androgenetic alopecia tx
Minoxidil (Rogaine)
Spironolactone (in females)
Cyproterone acetate in females (Diane 35)
Finasteride (5-alpha-reductase inhibitor)
Type of hair loss from chemotherapy
Anagen effluvium
Type of hair loss from stress
Telogen effluvium
Scarring alopecia
Irreversible loss of hair follicles with fibrosis
Always requires biopsy
Erythema Nodosum
Acute or chronic inflammation of subctuaneous fat DDx: NODOSUMM No cause Drugs (sulfa, OCP) Other infxns (GAS, TB) Sarcoidosis UC < CD Malignancy (leukemia, Hodkin's lymphoma) Many infxns
Most common type of melanoma
Superficial spreading
3 most important determinant of prognosis of melanoma
Tumour thickness
Histologic ulceration
Mitotic rate
Onychomycosis
Most commonly caused by dermatophytes (specifically Trochiphyton rubrum)
Paronychia
Nail fold infection
Commonly caused by Staph aureus or Strep pyogenes
Tx: Topical Gentamycin
Acute radiation dermatitis
Moist desquamation
Can occur acutely, late or “radiation recall”/months-years after
Improved by using intensity modulated radiation therapy (allows maximum focus on tumour while minimizing radiation to surrounding tissues)
