Dermatology Flashcards
Keratoacanthoma
- Variant of SCC
- Rapid growth
- Generally benign behavior
- Carteriform (volcano) morphology
- Can appear similar to BCC but the history will explain raid growth to help differentiate; BCC would take months to years to reach the stage of this lesion
Hutchinson’s sign: leeching of pigment onto skin around nail
- Highly aggressive melanoma
Amelanotic Melanoma
Keratoancanthoma
- Variant of SCC
- Rapid growth
- Generally benign behavior
Subungal Melanoma (involves nail matrix)
Talon Noir (Black heel)
- Intraepidermal hemorrhage
- Harmless, asymptomatic, due to trauma
Superficial Spreading Malignant Melanoma (SSMM)
- Most common form of melanoma
- Radial growth phase: 2-5 years
Superficial Spreading Malignant Melanoma (SSMM)
Lentigo Maligna Melanoma (sun exposed areas)
- Prolonged radial growth phase (5-15 yrs)
- Late vertical growth phase
- Best prognosis type of melanoma (if diagnosed during radial growth phase)
Nodular Melanoma
- Short or non-existent radial growth phase
- Early vertical growth phase
- Early metastasis
- Poor prognosis
Acral Lentiginous Melanoma
- Early metastasis
- Digits, ears, nose
- Aggressive variant of melanoma that generally portends a poor prognosis
Basal Cell Carcinoma (BCC)
- Rolled edge
- Translucent
- Central ulcer is common
- Telangectasia
- Sun-exposed areas
- Clinical variants
BCC
Cystic BCC
Broken down BCC
Advanced cystic BCC
Eroded cystic BCC or rodent ulcer
Pigmented BCC
Superficial BCC
Morpheaform BCC
- Morphea-like (scar-like)
- Sclerosis
- Most aggressive variant
- Therapeutic challenge; Mohs surgery
Actinic keratosis (precancerous lesion for SCC)
Actinic Keratosis (precancerous lesion for SCC)
Squamous Cell Carcinoma (SCC)
- Low risk of metastases except for the following: lips, eyes, lesions arising from scars or in the context of immunsuppression
SCC
SCC
SCC of lip
- Actinic cheilitis is the precursor lesion
Bowen’s Disease
- Squamous cell carcinoma in situ
- Sharply demarcated erythematous plaque with scale and/or crusting
- Often 1-3 cm in diameter and found on the skin and mucous membranes
- Evolves into SCC in 10-20% of cutaneous lesions and >20% mucosal lesions
Cherry Hemangioma or Capillary Hemangioma
Epidermal Inclusion Cyst
“Sebaceous cyst”
Xanthelasma
Pilar Cyst
Melasma
Halo Nevi
Sebhorrheic Keratosis
Herpes Simplex Type 1
Herpes Zoster
Genital Warts
Condyloma Acuminata
Cystic Acne
What is the etiology of acne vulgaris?
Acne Vulgaris Etiology
- Increasing effect of hormones in puberty on target organ - follicular sebaceous unit
- Androgens stimulate sebaceous glands to produce sebum
- Increased sebum production
- Hyperkeratinization of the follicular infundibulum
- Hyperkeratinization at the follicular ostia (opening), blocks the secretion of sebum (microcomedones)
- Overgrowth of Proprionbacterium acnes
- P. acnes contain lipase which converts sebum to free fatty acids and produces pro-inflammatory mediators
Rosacea
- Begins with flushing/blushing
- Red complexion and telangectasia worsen
- Next develop inflammatory papules and pustules
- May settle with oral antibiotics
- Maintenance with topical therapy
- Chronic lifelong course, but usually controlled with treatment
- Rare to see significant rhinophyma compared to the past
- Some people feel stigma of looking like an alcoholic due to red bulbous nose
Perioral Dermatitis
- Predominantly women aged 15-40 yrs
- Young children and elderly also affected
- Uniform sized tiny erythematous papules/pustules
- May coalesce to form scaling erythematous patches
- Can be itchy or burning at times
Seborrheic Keratosis
- Waxy, with a warty “stuck on” appearance, may be any color
- One of the most common tumors
- Genetic predisposition
- Usually begin to appear in 40s, increase with age
- Not related to sun exposure
- No malignant transformation
- Treatment: none, liquid nitrogen cryotherapy, electrodessication, curettage, surgical excision
Solar Lentigo
- Found in 90% of people >60 yrs
- Incidence increases with age, “age spots”, but may develop at any age
- Well circumscribed, sun exposed areas
- May fade slightly with avoidance of UV
- Treatment: counsel regardng sun protective measures, light cryotherapy, intense pulse laser
Halo Nevus
- Usually asymptomatic
- Central nevus may or may not involute with time
- Repigmentation often takes place over months or years; however, it does not always occur
- More common in kids, usually multiple
- Halo of regressing melanoma is irregularly shaped
- New halo nevus in an older adult warrants a biopsy (this could be a regressing melanoma)
Blue Nevus
- Early age of onset (8-15 yrs)
- Well defined homogenous blue-gray/blue-black color
- Commonly found on head and neck, dorsal hands and feet, presacral area
Spitz Nevus
- Red or pigmented papule or nodule, usually in kids or young adults
- Looks like melanoma on histology but doesn’t behave like melanoma
- “Juvenile melanoma”
- Grows rapidly, may reach size of 1cm within 6 months and then usually doesn’t change except color
- Treatment: complete excision is required
Pigmented Spindle Cell Nevus of Reed
- Variant of Spitz nevus
- Small, well circumscribed dark brown to black papule
- Characteristic starburst pattern on dermoscopy
Congenital Nevus
- Large lesions have a 3-12% risk of developing melanoma
Intradermal Nevus - raised, soft and fleshly papules of any color
Nevus Spilus
- Tan patch with superimposed “speckles” that develop over time
- Common on trunk and extremities
- Reports of melanoma developing within these lesions, therefore, following them with serial imaging is a good idea
Dermatofibroma
- Very common tumor in adults
- Lower extremities
- Firm, usually 5-10mm in size, + dimple sign
- Etiology unknown, theory = reaction to insect bite
- Spindly tumor, “scar-like” center, may produce worse scar or recur if biopsied
- Biopsy only if diagnosis is in question or itchy
Atopic Dermatitis - chronic/relapsig pruritic dermatitis usually associated with a personal or family history of atopy
- Pathognesis: environment and genetics, mutations in filaggrin, barrier dysfunction, immune disregulation
- Most cases are diagnosed before the age of 5yrs
- 80% will develop allergic rhinitis or asthma later in childhood
Clinical Features
- Acute: intense pruritus, erythematous papulovesicles, excoriations, exudation, secondary infection
- Sbacute: excoriated, erythematous scaly papules and plaques
- Chronic: lichenification
Distribution
- Infancy: scalp, face, extensor extremities-spared, diaper area
- Childhood: flexural
- Adulthood: flexural, hands, face, nipples
Treatment: irritant avoidance, nonsoap cleanser, emollients, baths, topical corticosteroids, topical calcineurin inhibitors (tacrolimus, pimercrolimus)
Sebhorrheic Dermatitis - a subactue or chronic dermatitis of unknown cause typically confiend to sebaceous gland-rich skin of the head and trunk but occasionally involving intertriginous areas
Clinical Presentation
- Scalp, ears, face, central chest and intertriginous areas
- Pink-yellow to red-brown plaques with bran like to greasy scale
- No or minimal itching except scalp in adults
- Infantile = onset 1 wk, cradle cap
- Adult = scalp>face>central chest and intertriginous areas, dandruff is in same disease spectrum
Nummular Dermatitis - coin shaped (discoid) plaques that vary from papulovesicular and exudative to red and scaly
Clinical Presentation
- Symmetrical
- Extremities
- Well-demarcated
- >50 yrs old; increases in prevalence as age increases
- Usually very pruritic
- Chronic course
- Associated with xerosis, infection?, and other types of dermatitis
Nummular dermatitis
Contact Dermatitis - an inflammatory process caused by contact with an exogenous agent
Clinical Presentation
- Hands>face>general>arms
- Two types: allergic and irritant
- Most common allergens: nickel sulfate, neomycin sulfate, balsam of peru, fragrance mix, thimerosal
- Hands and face are most common sites for irritant contact dermatitis
- Acute irritant contact dermatitis: peaks within minutes to hours, burning stinging, soreness, erythema, edema, bullae, necrosis and ulceration, sharply demarcated, asymmetry
Erythema Nodosum - a reactive hypersensitivity reaction that may occur in response to a number of antigenic stimuli
- The most common form of panniculitis
- F>M, 20-30 yrs
- Panniculitis refers to inflammation of the subcutaneous fat
- Abrupt onset of ill-defined red, tender 2-4cm plaques or nodules on the anterior shins (occasionally elsewhere)
- The majority of patients with EN have evidence of recent streptococcal infection or have no identifiable cause
- Triggers: streptococcal infection, URTI, TB/virus/chlamydia/fungi, sacoidosis, IBD, drugs ex. OCP
- Individual lesions last 2 wks and resolve with bruise like color changes
- Ulceration not a feature (unlike some other kinds of panniculitis)
- Many patients have fever and generalized aching associated with onset of the skin lesions
- Arthralgia occurs in more than 50% of patients and begins during the eruptive phase or can even precede the eruption by 2-4wks
- EN associated with hilar adenopathy and can be accompanied by gastrointestinal symptomatology
Erythema Multiforme
- Abrupt onset of tender/painful macules or papules primarily on the hands and forearms, feet are sometimes involved
- The lesions are fixed and evolve to central blistering
- Mucosal erosions may be seen on the lips in some patients
- The single most important trigger is recent herpes simplex virus reactivation (it can be subclinical)
Erythema Multiforme - lip erosions, mucositis
Urticaria “Hives”
- Itchy and transient; the events of urticaria and angioedema are due to activation of dermal mast cells and therefore, histamine
- Wheal: red, edematous papule or plaque which may develop central blanching (makes a ring)
- The plasma leakage is in the superficial dermis
- Well-demarcated
- No surface change (scaling, exudation or crusting)
Angioedema
- Angioedema arises from edema of the deep dermis, fat or the submucosal tissues
- The swelling is often painful, poorly defined, pale or skin colored
- Lesions can last 24-72 hrs
- ~50% of patients with chronic urticaria have coexistent angioedema
Exanthem
- A rash of actue onset and widespread (symmetric) distribution
- Consists of blanchable red spots
- These spots can be macules or papules
Exanthem - Maculopapular Eruption
- The most common examples of exanthemous eruptions are often called maculopapular; synonymous with morbilliform
- The spots are typically monomorphic
Exanthem - Scarlatiniform eruption
- Any rash of acute onset with a picture of diffuse (sunburn-like) erythema is appropriately called scarlatiniform
- Scarlet fever: toxigenic process mediated by streptococcal exotoxin
- Fever
- Sore throat
- Abdominal pain
- Malaise
Primary Syphilis - Chancre
- Painless
- Macule to papule to erosion to ulcer
- Clean base with serous exudate
- Indurated
- 40-50% have multiple chancres
- Chancre redux, pseudochancre redux
- Can last weeks untreated
- Balanitis presentation
- 15% of people with secondary syphilis still have chancre when they present with rash
Secondary syphilis - papulosquamous rash
- Secondary syphilis is likely to be a generalized rash, it is one of few things that can cause an eruption on the palms and soles
Secondary Syphilis - Condyloma Lata
- Secondary syphilis involves rash, alopecia, bone pain, condyloma lata
Congenital Syphilis - “Snuffles”
- Congenital Syphilis: “snuffles”, hepatosplenomegaly, desquamation, long bone abnormalities, mucous patches, perforation of palate, hutchinson’s teeth, “mulberry molars”, bone/cartilage malformations, sabre shins
Impetigo
- S. Aureus
- Group II, Phage type 71
- Rapidly evolving generalized exfoliative disease of young infants
- Organism at a distant site
- Starts as a bulla but rubs off and then crusts are left
Staph Scalded Skin/Bullous Impetigo
- S. Aureus
- Group II, Phage type 71
- Epidermolytic toxin separates skin below the stratum corneum
- Fragile bullae break easily
- Systemic symptoms as a reaction due to endotoxin
Folliculitis
- S. Aureus
- Small white pustules around the opening of a hair follicle
- Factors such as depilatories, shaving, elevated ambient temperature and humidity are predisposing conditions
Furuncle
- Deeper folliculitis AKA boil
- Tender and hot
- Single draining opening
Carbuncle
- Multiple deep communicating furuncles
- Multiple draining openings
- S. Aureus
Ecthyma
- Punched out deep ulcers
- Strep pyogenes
- Often heal with scarring
Cellulitis
- Deeper seated infection
- S. Aureus
- Local erythema and swelling which spreads rapidly
- May be associated with lymphangitic spread
- Skin will often show superficial necrosis after several days without treatment
- Systemic symptoms often present; B-symptoms, sepsis
Lymphangitis
- Inflammation tracking up lymphatic vessels
- Can happen with chemotherapy
- Strep infection
Erysipelas
- Acute beta hemolytic group A strep
- Involving superficial dermal lymphatics
- Sharply marginated painful plaque
- May have systemic symptoms
Varicella
- Herpes zoster virus (HZV)
- Acute episode results in chicken pox
- Dew drop on a petal
- Febrile illness
- Lesion appear in 3 successive crops
- Heal in 10-14 days
Zoster
- Reactivation of HZV
- Like all herpes viruses, the lesions are grouped vesicles on an inflammatory base
- Dermatomal in distribution
- Major complication is post herpetic neuralgia
Verruca Vulgaris
- Warts
- Human papilloma virus
Verruca Plana
Molluscum Contagiosum
- Pox (DNA) virus
- Umbilicated papules
- In sexually active adults it is considered an STI
Dermatophyte Infection
- Three majory genera: trichophyton, microsporum, and epidermophyton
- This is a red and scaly patch, it can be blisters/pustules or annular plaques
- The reaction on the skin is the host response
- Microsporum is endemic in cats so people can be infected by their cats
Kerion
Tinea Pedis
Tinea Unguis
Candidiasis
- Candida albicans
- Mouth - oral thrush
- Skin folds
- Intertrigo
- Satellite lesions common
Candidiasis
- Candida albicans
- Mouth - oral thrush
-
Skin folds
- Intertrigo
- Satellite lesions are common
Tinea Versicolor
- Malassezia globosa
- Species of yeast
- A normal colonizer of adult skin
- ‘Funny’ rash on the chest with a very fine scale on the surface
- The small patches are versicolor: can be red, brown or white
- This may be caused by heat and the organism attraction to sebum in the skin
Scabies
- Sarcoptes scabeii
- Intesely pruritic
- Burrows found on hands in adults
- In young children also found on occipital scalp and feet
Scabies
- Scabies lifecycle:
- Adult females deposit eggs as they burrow
- Eggs hatch releasing larvae
- Larvae molt into nymphs, larvae and nymphs are found in short burros called molting pouches
- Mating occurs after the male penetrates the molting pouch of the adult female
- Impregnated females extend their molting pouches into burrows, laying eggs
- Transmission is person to person and fomites ex. bedding and clothing
- Mites are found predominantly between fingers and on the wrists
- Rash presents on back, buttocks, elbows, knees, axilla, genital areas
Lice
What are the 3 most common causes of alopecia?
- Alopecia areata
- Telogen effluvium
- Androgenic alopecia
What is the pathognomonic feature of alopecia areata?
Exclamation point hairs
In alopecia areata, what factors suggest poorer prognosis?
A. Younger age at onset
B. Ophiasis pattern
C. Extent of involvement
D. All of the above
E. None of the above
D. All of the above: younger age at onset, ophiasis pattern, extent of involvement
How would you classify her alopecia?
A. Scarring diffuse
B. Scarring patterned
C. Non-scarig diffuse
D. Non-scarring patterned
D. Non-scarring patterned
What are the steps for the initial management of a major burn?
Management of Major Burn
- Remove clothes - stop the burning process
- Major burn = Trauma
- Follow ATLS protocol
- Airway, Breathing, Circulation (ABCs)
- Complete primary survey and obtain history
- Secondary survey
In a major burn patient, how do you address circulation (ABCs)?
Circulation
- Start 2 large bore peripheral IVs
- Ringer’s Lactate
- In order to calculate the amount of fluid, need to know:
- History and amount time since burn occurred
- Depth of burn
- Total body surface area burned
How do you determin the amount of IV fluid required in a major burn patient?
Parkland Formula: Ringer’s Lactate
- Amount of IV fluid required in 24 hrs = 4cc x wt (kg) x % TBSA burn
- Give half of fluid in first 8 hrs
- Give second half in the next 16 hrs
How do you monitor fluid resuscitation of a major burn patient?
Fluid Resuscitation Monitoring
Urine output via Foley Catheter
- Aim for 0.5-1.0cc/kg/hr
- Color of urine: electrical burns and myoglobinuria (renal failure, compartment syndrome)
- Assess: mental status, capillary refill, temperature of extremities
- Investigations: electrolytes, creatinine, urea
Define macule.
A macule is a lesion that is <1cm and flat.
Define papule.
A papule is a lesion that is <1cm and elevated.
Define a patch.
A patch is a lesion that is >3cm and flat.
Define a plaque.
A plaque is a lesion that is >3cm and elevated.
Define a vesicle.
A vesicle is a fluid filled lesion <1cm.
Define a bullae.
A bullae is a fluid filled lesion >1cm.
Pityriasis Rosea
- Herald patch occurs before the rest of the eruption
- Occasionally is preceded by mild URTI
- Crop of lesions appear rapidly over the trunk, neck, upper arms and legs; lesions follow Langer’s skin lines
- Often seen in clusters
- Spontaneously resolve in 1-2 mths
- Recurrences extremely rare
- Salmon colored, trailing scale, oval
Lichen planus
- PAPULE
- Flat topped, polygonal, purple papules
- Idiopathic, pruritic, inflammatory condition
- Ankles, wrists, mouth, genitalia
- Can have Koebner’s phenomenon
- Lesions often hypertrophic over lower legs
- Buccal mucosal lesions are common; white streaks in reticulated ‘lacey’ pattern
Lichen planus
- PAPULE
- Flat topped, polygonal, purple papules
- Idiopathic, pruritic, inflammatory condition
- Ankles, wrists, mouth, genitalia
- Can have Koebner’s phenomenon
- Lesions often hypertrophic over lower legs
- Buccal mucosal lesions are common; white streaks in reticulated ‘lacey’ pattern
Herpes Simplex
- HSV 1 and 2
- Grouped vesicle on an erythematous base
- Vesicles
- Primary infection and recurrences
- Sites of predeliction:
- HSV1 labial skin
- HSV2 genital skin
- Neonatal herpes
Impetigo
- Primarily caused by group 2 S. Aureus
- Usually neonates or young children
- Fragile bullae which rupture leaving weeping and crusted patches
Hemangioma
- Common, 3% of population
- Red “strawberries”
- Obviously vascular
- Involute spontaneously in 90% of cases
- No treatment unless growth interferes with a vital structure such as the eye or oropharynx
What are the ABCDEs of lesions?
What are the nail changes present in psoriasis?
Nail pits
Onycholysis: nail plate separation
Oil drop sign
Auspitz’s Sign - individual silvery scales are plucked form psoriatic plaques, tiny pinpoint capillary bleeding may be seen
True or false. Dark field microscopy is the most sensitive test for syphilis.
FALSE
The RPR (Rapid Plasma Reagin) is specific for syphilis. T or F.
FALSE. It is NOT specific.
Endocarditis does not cause a false positive test in the context of syphilis screening. T or F.
FALSE. Endocarditis can give a biologic false positive test.
For contact dermatitis which would of the following would you complete?
Prick testing
Scratch testing
Punch biopsy
Patch testing
PATCH testing
