Dermatology Flashcards
Name the lesion:
<1cm flat discoloured lesion
Macule
Name the lesion:
>1cm flat discoloured lesion
Patch
Name the lesion:
<1cm palpable raised lesion
Papule
Name the lesion:
>1cm palpable raised lesion
Plaque
Name the lesion:
<1cm lesion with significant depth
Nodule
Name the lesion:
>1cm lesion with significant depth
Tumor
Name the lesion:
>1cm fluid-containing lesion
Cyst
Name the lesion:
dilated superficial blood vessels
Telangiectasia
Name the lesion:
elevated lesion containing pus
Pustule
Name the lesion:
<1cm elevated lesion containing serous fluid
Vesicle
Name the lesion:
>1cm elevated lesion containing serous fluid
Bulla
Name the lesion:
transient blanch able papule or plaque
Wheal
Name the lesion:
scratch mark on the skin
Excoriation
Name the lesion:
area of diffuse thickening with increase in surface skin markings due to rubbing or scratching
Lichenification
Name the lesion:
increased stratum corneal cells shedding
Scales
Name the lesion:
dried exudates of blood, serum or pus
Crusts
Name the lesion:
linear break in skin
Fissure
Name the lesion:
shallow complete or partial loss of epidermis, heals without scarring
Erosion
Name the lesion:
irregular excavations extending into the dermis or deeper
Ulceration
Name the lesion:
thinning or depression of skin
Atrophy
Name the lesion:
connective tissue formations that replace lost tissue
Scar
Name the lesion:
decreased skin pigment
Hypopigmentation
Name the lesion:
increased skin pigment
Hyperpigmentation
Name the lesion:
depigmentation
Complete absence of skin pigment
What does Rickettsia rickettsii cause?
RMSF
- serious illness caused by the tick-borne bacterium
Dx
- sudden onset fever, headache, rash
- history of tick bite
+/- nonspecific sx (myalgia, GI complaints)
RMSF
- can lead to irreversible damage to internal organs and death if not treated correctly
Ddx erythematous macules
- blanchable and diffuse lesions
- drug eruption
- infectious exanthems
- secondary syphilis (palms and soles)
- rheumatic fever (erythema marginatum)
- RMSF (early stages, sparing palms and soles)
Ddx photodistributed macules
Phototoxic drug reaction
- NSAIDs, quinolone, tetracyclines, amiodarone, phenothiazines
- exaggerated sunburn: erythema, deem, vesicles/bullae
Photoallergic drug reaction
- soaps, fragrances (photoallergen and UVA interaction)
- pruritic eruption indistinguishable from allergic contact dermatitis
-> location face, V of upper chest, dorsa of hands and forearms, sun-exposed areas
Dx
- erythema in malar distribution (butterfly rash) or
- diffuse erythema in photodistribution
SLE lesions
Dx
- violaceous, periorbital heliotrope rash with edma
- erythema of neck and upper trunk (shawl sign)
- violaceous papule over knuckles (Gottron papules)
Dermatomyositis lesions
Dx
- overgrowth M. furfur
- mottled distribution of round/oval hyper- or hypopigmented macules with fine scaling (positive grattinage)
- often on trunk
How do you diagnose? Tx?
Tinea versicolour (Pityriasis Versicolor)
Dx via hyphae and spores on KOH prep (spaghetti and meatballs)
Tx
- Selenium sufide lotion
- oral Ketoconazole
Dx
- autoimmune reaction against melanocytes; associated with other autoimmune diseases (pernicious anemia, Hashimoto thyroiditis, DMT1)
- acquired dipigmented macules or patches with sharp margins
- isolated or generalized; often around eyes, mouth, digits, extensor surfaces, low back, genitalia
How do you dx? Tx?
Vitiligo
Dx - wood lamp to distinguish hypo pigmentation from depigmentation
- no melanocytes on histology or microscopy
- lab tests if thyroid disease, DM or pernicious anemia suspected
Tx
- sun protection, camouflage preparations
- regimentation with narrow band UVB, topical corticosteroids or topical immunomodulators
- depigmentation for extensive disease with topical agents
Dx
- often following acne, psoriasis, lichen plans, atopic dermatitis, trauma
- often limited lesions to site of inflammation
- indistinct borders
- often darker skin types
Tx?
Postinflammatory hyperpigmentation
Tx
- observation (most cases resolve spontaneously)
Dx
- F>M
- if from sun exposure, triggered by pregnancy and exogenous hormones
- acquired well-demarcated geographic-patterned macules and patches with irregular margins
- commonly on central face (cheeks, forehead, nose, upper lip)
Tx?
Melasma
Tx
- may regress spontaneously
- skin-lightening agents: hydroquinone, azelaic acid, tretinoin, kogic acid
- chemical peels
- sun protection
Dx
- adverse drug reaction occurring in same location
- sharply marginated, round/oval, erythematous macules evolving to plaques, bullae, and erosions; recurrent episodes may leave prominent hyperpigmentated macules or patches
Dx? Tx?
Fixed drug eruption
- fixed because recurs at same location
Dx - clinical; drug challenge/ withdrawal
Tx
- stop offending agent
Dx
- abnormal follicular keratinization, increased sebum secondary to androgens, Propionibacterium acnes (bacteria), inflammation
- combination of comedones, papules, pustules, and if severe nodules and cysts
Dx? Tx?
Acne Vulgaris
Dx
- non-inflammatory = open (black heads) and closed (white heads) comedones
- inflammatory = papule, pustules, cysts, nodules; deep lesions leave scars
Tx mild - topical antibiotics (clindamycin/erythromycin) - benzoyl peroxide - topical retinoids - salicylic acid moderate - add PO abx (minocycline/ doxycycline/ tetracycline) - OCP/ antiandrogens in females severe - PO isotretinoin
Dx
- pruritic, red macules and papules
- begins on face and spreads to neck, trunk and extremities; takes 24h
- red macules and papules are present on soft palate (Forchheimer sign)
Rubella
Dx
- erythematous macules and papules
- begin on face and spread cephalocaudally
- small white spots (Koplik spots) can be on oral mucosa
Measles
Dx
- bright red cheeks
- followed by symmetric erythematous eruption on trunk and extremities
Erythema infectiousum
Dx
- pink macules and papules
- lesions surrounded by white halos
- begins on trunk and spreads to neck and proximal extremities
Roseola
Dx
- chronic inflammatory disorder of pilosebaceous units and vasculature of face
- sebaceous hyperplasia and seborrheic dermatitis more common
- erythema, telangiectasis, papules, and pustules of central face; no comedones (vs. acne)
Variants? Triggers? Tx?
Rosacea
Variants
- Stage 1 -erythema and telangiectases
- Stage 2 -papulopustular rosacea; nodules may be present if severe
- Stage 3 -hyperplastic and phymatous rosacea (e.g. rhinopehyma) - coarse facial features plus soft tissue hyperplasia
Triggers
- hot drinks, spicy food, EtOH
- sun, heat
Tx
- topical metronidazole
- oral abx (minocycline/ doxycycline/ tetracycline)
- laser for telangiectasia or rhinophyma
Dx
- chronic, recurrent inflammatory skin condition with abnormal epidermal differentiation and hyper proliferation
- commonly seen on elbows, knees, scalp, nails, intergluteal folds, palms and soles
- consist of well-demarcated red papules and plaques with classic silvery scale
- nail changes (pitting, oil drops, onycholysis, sublingual hyperkeratosis)
Tx?
Psoriasis
10-30% associated with psoriatic arthritis
Tx body lesions - medium-high potency corticosteroid topical - calcipqotriol - tar - antralin - tazarotene - intralesional triamcinolone - phototherapy (UVB, PUVA) - systemic rx (methotrexate, acitretin, cyclosporin) facial/ intertriginous lesions - low-potency corticosteroid - tacrolimus/pimecrolimus scalp - tar shampoo - topical corticosteroid - calcipqotriol solution - tazarotene
What is Koebner phenomenon?
- physical trauma to skin = psoriasis plaque to form
What is Auspitz sign?
- scale removal (psoriasis) causes appearance of minute droplets of blood (not routinely tested)
Dx
- acute or chronic inflammatory disorder affecting the skin, mucous membranes, nails
- pruritic purple, polygonal, planar (flat-topped) papules and plaques mainly on inner wrists, torso and extremities; overlying Wickham striae often seen
- white reticulated lesions of mucosal surfaces (lips, buccal mucosa)
Tx?
Lichen Planus
r/o drug-induced lichenoid reaction
Tx
- topical corticosteroids
- systemic agents in widespread cases (acitretin, cyclosporin)
Has lichen planus been associated with Hepatitis A, B or C?
Hep C (rare cases) - if pt has RF then test!
Dx?
- inflammatory acneiform skin condition
- may be exacerbated by topical steroid abuse
- 1-2mm erythematous papulopustules distributed personally, with sparing of vermilion border
- occasional periorbital distrubution
Tx?
Perioral dermatitis
Tx
- topical metronidazole
- topical erythromycin
- systemic abx (minocycline/ doxycycline/ tetracycline)
What percentage of hemangioma regress by age 7?
70%
What is a classic finding of a dermatofibroma?
Dimple sign
- pinching causes dimpling into surrounding skin
Dx
- melanocytes nevi, or moles = pigmented macules, papules, or nodules arising from the proliferation of melanocytic nevus cells
Subtypes?
Nevus
- junctional nevus
- compound nevus
- dermal nevus
- congenital nevus
- dysplastic/ atypical nevus
- halo nevus
- blue nevus
Dx
- derived from epidermis or epithelium of hair follicle
- formed by cystic enclosure of epithelium within the dermis that becomes filled with keratin and lipid-rich debris
- dermal-to-SC nodule connected with surface by keratin-filled pores
Epidermoid cyst
Dx
- superficial white-yellow keratin containing epidermal cyst commonly found on cheeks and eyelids
Milium
Dx
- pseudocyst that presents at bay of nail of finger or toe or on distal interphalangeal joint
- associated with Heberden node
Digital myxoid cyst
Dx
- hyper pigmented papules and plaques with warty surface and ‘stuck on’ appearance
- increase incidence with age
Seborrheic keratosis
Dx
- smooth papules with central umbilication and telangiectasia
- common in elderly and tx with cyclosporin
Sebaceous hyperplasia
Dx
- benign, soft, rounded or lobulated subcutaneous tumors that are easily movable against overlying skin
- composed of normal fat cells and commonly found on neck, trunk, extremities
Lipoma
Dx
- common button-like nodule presenting on extremities
- often domed, raised, dermal red-brown nodule, but may be depressed
- can be associated with history of insect bite or ruptured cyst
Dermatofibroma
Dx
- result from fibrous repair tissues after injury
- confined to original injury site vs. extend beyond original injury site
Hypertrophic scar = confined to injury site
Keloid scar = extend beyond injury site
What is Gardner syndrome?
- rare autosomal dominant condition associated with colon cancer, in which multiple epidermal inclusion cysts are found and is assisted with osteoma, extracolonic, and demoed tumors
Dx
- pearly papule or nodule with peripheral telangiectasis (multiple other presentations possible)
- metastasis rare
Tx?
BCC
Tx
- surgical excision
- Mohs micrographic surgery
- electrodissection and curettage
- cyrotherapy
- radiation
- topical imiquimoc, 5-fluorouracil
- photodynamic therapy
Dx
- sharply demarcated scaling or hyperkeratotic papule, plaque or nodule
- metastasis 5-10%
Tx?
SCC
Tx
- surgical excision
- photodynamic therapy for superficial SCC (in situ)
- topical imiquimod (Bowen disease)
What is potential precursor to SCC? Tx?
Actinic keratosis
- cyrotheraphy or imiquimod
RF BCC and SCC?
RF
- UV light (esp UVB)
- ionizing radiation exposure
- chronic immunosuppression
- smoking
- phototherapy with psoralens
- chronic ulcers/ scars
- arsenic ingestion
- actinic keratoses
Prevention BCC and SCC?
- sun avoidance and protection
- avoidance or protection from carcinogenic chemicals (arsenic)
- regular skin self-exam
ABCDE malignant melanoma? Does it metastasize?
Tx?
Asymmetry Border irregularities Color variegation Diameter >6mm Evolution
- mets common
Tx surgical excision - in situ = 0.5 cm margins - <2mm thick = 1 cm margins - >2mm thick = 2 cm margins \+/- LN dissection, adjuvant tx with chemo (interferon alpha 2-b)
RF malignant melanoma? Prevention?
RF
- skin type I/II (fair, red hair, blue eyes)
- dysplastic nevus syndrome
- congenital nevi
- multiple atypical nevi
- personal hx melanoma
- FHx atypical nevi or melanoma
- excessive sun exposure, especially sunburns during childhood and tanning bed use
- immunosuppression
- genetic markers (CDKN2A mutation)
Prevention
- sun avoidance and sun protection
- screen pt with FHx, dysplastic and multiple nevi
- regular skin self-exam
What is the most common clinicopathologic subtype primary cutaneous T-cell lymphoma? How does it present? Treatment?
Mycosis fungoides
- presents has thin scaly red plaques in ‘bathing suit’ distribution - can progress to plaques, nodules or tumors
- leonine facies if extensive infiltration
Tx
- topical corticosteroid
- nitrogen mustard
- narrow band UVB, PUVA
- total body electron beam therapy
Dx
- autoimmune bullous skin disease affecting middle-aged or elderly pt
+/- pruritus
- widespread blistering eruption on erythematous or normal skin base
- erosions may be present after vesicles/ bullae burst
- flexure areas, groin and axilla are commonly involved
- oral lesions less common
Tx?
Bullous pemphigoid
Tx
- topical strong steroids for localized disease
- PO prednisone/ steroid-sparing agents (methotrexate azathioprine, mycophenolate mophetil)
Dx
- serious autoimmune blistering disease affecting pt 50-60 yr
- painful skin lesions and/or oral mucosae
- pruritus uncommon
- flaccid blisters or epidermal bulla, or residual erosions
- mouth ulcers common and often initial presentation
- hyper pigmented patches can be seen after lesions healed
- nonscarring
Tx?
Pemphigus Vulgaris
Tx
- hospital admission to burn unit prn
- Prednisone high dose then steroid-sparing agents started early disease while tapering prednisone: azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide, IVIG
- Abx if secondary infection
What is Nikolsky sign?
Rubbing skin causes separation of epidermis and formation of new blister
What is Asboe-Hanson sign?
Rubbing lesion in lateral direction causes it to extend
Dx
- common viral infection affecting oral-facial vermilion border or genital mucosa
- subclinical primary episode or several days of fever, malaise, lymphadenopathy, oral mucosal erosions
- may be reactivated by stress, fever, UV light, trauma
- grouped umbilicated vesicles on erythematous base; burning and itching may be preceding
Dx? Tx?
HSV-1 and HSV-2
Dx
- Tzanck smear - multinucleate giant epithelial cells
- viral culture or PCR from lesion swab
- antibody testing of fluid from base of vesicle
Tx
- often supportive
- PO antiviral may reduce pain, viral shedding, healing time if within 72h
- topical antivirals not beneficial
What is herpes on fingertip?
Herpetic whitlow
What is eczema secondarily infected with herpes?
Eczema herpeticum
Dx
- primary infection with VZV (chickenpox)
- reactivation can be triggered with immunosuppression of stress
- clusters of erythematous papules and vesicles commonly following pain in unilateral dermatomal distribution
- lesions eventually crust and desquamate
Tx? Complication?
Herpes Zoster (shingles) - can result in postherpetic neuralgia
Tx
- supportive
- PO antiviral may reduce pain, viral shedding and healing time if within 72h
- topical no benefit
Dx
- acute life-threatening mucocutaneous disorder with extensive necrosis and detachment of epidermis
- often caused by drugs (carbamazepine, phenytoin, allopurinol, lamotrigine, NSAIDs, sulfa drugs)
- life-threatening because multi system involvement
- purpuric and erythematous macules -> flaccid blisters involving trunk, upper limbs, mucous membranes (buccal, genital, ocular)
- positive Nikolsky sign
Tx?
Stevens-Johnson Syndrome
- <10% BSA
Toxic Epidermal Necrolysis
- >30% BSA
- overlap = 10-30% BSA re: total area of detached/ detachable epidermis
Tx
- d/c culprit drug
- supportive (burn unit, ICU), ophthalmology assessment
- abx if infection
- IVIG (controversial)
What is pruritus?
- sensation provoking desire to scratch
What type of hypersensitivity reaction is urticaria?
- type I (IgE mediated)
Dx
- hypersensitivity reaction characterized by severe pruritus and dry skin; associated with personal of FHx of atopy (asthma, eczema, hay fever)
- aggravated by inhalants, winter, wool, emotional stress, excessive hand washing, foods
- erythematous patches/ papules/ plaques
- associated scales, crusts, excoriations from scratching or secondary infection
- lichenification, fissures and Dennie-Morgan folds
Stages?
Atopic dermatitis
Stages
- infantile - extensor surfaces, face, scalp
- childhood - flexural surface, lichenification
- adult - hand eczema, xerosis
What is thickening of skin with accentuated skin markings?
Lichenification
Where are Dennie-Morgan folds?
- infraorbital eyelid fold
Dx
- excoriations from scratching; commonly start on palms and soles then generalized
- jaundice
Causes? Tx?
Causes
- PBC (pruritus = presenting sx in 50%)
- renal disease
- cholestasis of pregnancy
- cholestasis from drugs
Tx
- bile acid resins (cholestyramine, colestipol)
- opioid antagonist (naloxone)
What endocrine disorders can cause pruritus?
- thyrotoxicosis (increased blood flow)
- hypothyroid (xerosis)
- DM (anhidrosis, infection)
gastric carcinoid - histamine flush
General tx for pruritus?
Topical
- cooling agents (menthol)
- emolients
- topical corticosteroids
- anesthetics
- capsaicin
Phototherapy - UVB
Systemic
- H1 antihistamines (hydroxyzine, doxenin)
- systemic corticosteroids
- opioid receptor antagonist
Other
- TENS
- acupuncture
Alopecia vs. cicatricial alopecia?
alopecia = hair loss
cicatricial alopecia = hair loss with fibrosis and scar tissue (scarring alopecia)
Most common cause of noncicatricial alopecia in men and women?
Androgenic alopecia
What deficiencies can cause depigmentation of hair shaft?
- protein and copper deficiency
What is increased daily hair loss triggered by physical or mental stressor to body?
Telogen effluvium
What is autoimmune disease causing localized round or oval patches of hair loss? Or all scalp hair lost? Or all body hair lost?
Alopecia Areata
scalp = alopecia totalis
body = alopecia universals
Investigations for alopecia?
- CBC
- ferritin
- TSH
- if fungus suspected: microscopic exams and fungal culture
+/- scalp biopsy, ANA, androgens
What is the separation of nail plate from nail bed?
Onycholysis
What is the severe thickening of the nail plate with deformed shape?
Onychogryphosis
What is a chronic fungal infection where the nail plate becomes yellowed, thickened, and dystrophic?
Onychomycosis
Organisms causing infections of nails (acute vs. chronic)?
Acute: S. aureus
Chronic: C. albicans
Ddx finger clubbing
- CVD
- lung disease
- GI disorders
- chronic methemoglobinemia
Ddx koilonychia (hollow/sppon shaped)
- iron deficiency
- malnutrition
- DM
- old age
Onychomycosis fungal infection organisms?
- T rubrum
- T. mentagrophytes
Ddx transverse grooves/ Beau lines?
- acute significant systemic disease
Ddx transverse white lines/ transverse leukonychia
- hypoalbuminemia
- chemo drugs
- poisons
Ddx pitting to nail
- psoriasis
- alopecia areata
- eczema
- paronychia
- inflammatory damage
What nail change can tetracycline cause?
Yellowing of nail
Ddx splinter hemorrhages
- trauma (most common)
- bacterial endocarditis
- blood dycrasias
What is onychocryptosis?
Ingrown nails
- inflammation and soft tissue hypertrophy +/- secondary infection occurring when lateral edge of nail plate impinges on nail fold
Is generalized red rash with fever, vesicles, mouth lesions, purpura and/or generalized scaling concerning?
Yes - investigate promptly
What are derm emergencies?
Vesiculobullous disorders
- SJS/TEN
- pemphigus vulgaris
- bullous pemphigoid
Infections
- hemorrhagic fevers
- Leprosy (reversal rxn on tx) mucormycosis
- necrotizing fasciitis
- neonatal HSV
- RMSF
- still disease, trichinosis, tularaemia
Autoimmine
- systemic and neonatal lupus erythematosus
- dermatomyositis
Inflammatory cutaneous disorders
- acne fulminans
- acute drug eruption
- acute pustular psoriasis
- exfoliative erythroderma
- Kawasaki syndrome
- pyoderma gangrenosum
- scarring alopecia
Stigmata of liver disease?
- jaundice
- gynecomastia
- caput medusa
- loss of body hair
- palmar erythema
- peripheral edema
- purpura
- spinner angioma
Stigmata renal disease?
- photo distributed or diffuse hyper pigmentation (inc palms and soles), pallor, yellow tinge
Stigmata DM?
- acanthuses nigricans
- foot ulcers
- pruritus
- light brown slightly indented scaly patches (diabetic dermopathy)
- yellow skin and nails
Underlying conditions of pyoderma gangrenosum?
- UC
- Crohn disease
- RA
Stigmata Cushing syndrome?
- acanthosis nigricans
- acne
- buffalo hump
- hirsutism
- telangiectasia
- striae
- atrophic skin
Stigmata Neurofibromatosis
- cafe au last macules
- freckling
- multiple cutaneous neurofibromas
Stigmata Porphyria
- blister formation
- photosensitivity
- hypertrichosis
- pigmentation
- skin fragility
Stigmata hyperlipidemia
- xanthomas
