Dermatology Flashcards
Bacteria that proliferate immediately after a burn
Gram-positive skin flora (Staph Aureus)
> 5 days after a burn, most infections are caused by
Gram-negative organisms (Pseudomonas)
Fungi (Candida)
Early signs of wound infection
Change in appearance (partial thickness becomes full thickness)
Loss of viable skin graft
Burn wound sepsis
Can develop rapidly
Findings: Temperature < 36.5 (97.7) or > 39 (102.2) - Low temperature counts too! Weird! Progressive tachycardia (>90) Progressive tachypnea (>30) Refractory hypotension (SBP < 90)
Also common: Oliguria Unexplained hyperglycemia Thrombocytopenia AMS
Diagnosis of Burn Wound Sepsis
Quantitative Wound Culture (> 10^5 bacteria/g tissue)
Biopsy (determine tissue invasion depth)
Treatment of Burn Wound Sepsis
Empiric broad spectrum IV antibiotics
Pip/Taz
Carbapenem
Potentially include Vanc for MRSA coverage
Potentially include Aminoglycoside for MDR Pseudomonas
Local wound care & debridement
Definition of a large burn
> 20% of body surface area
You see a pediatric burn patient with uniformity of burned skin, sharp lines of demarcation & flexor surface sparing. What do you do?
Call child protective services
Child with: Recent infection Hematuria Abdominal Pain Lower extremity purpuric rash No thrombocytopenia
Vasculitis (probably HSP)
Treat with hyrdation & NSAIDS
Major risk factor for Actinic Keratosis
Chronic sun exposure
Surrounding skin often shows features of solar damage (telangiectasias, hyperpigmentation)
Clinical significance of Actinic Keratosis
Potential progression to squamous cell carcinoma
Likelihood of malignant progression of an individual lesion is low
When is a biopsy of Actinic Keratosis indicated?
> 1cm diameter Indurated Ulceration Rapidly growing Fail appropriate treatment (Cryotherapy or fluorouracil if large)
Histopathology of Actinic Keratosis
Acanthosis (Thickening of epidermis)
Parakeratosis (Retention of nuclei in stratum corneum)
Nuclear atypia
Abnormal keratinization w/ thickening of stratum corneum
Treatment for Actinic Keratosis
Cryotherapy
Large area may require field therapy (Fluorouracil)
Characteristics of Allergic Contact Dermatitis
Erythematous papules or vesicles
Lichenification in chronic cases
Triggers of Allergic Contact Dermatitis
Toxicodendron Plants (Poison Ivy)
Nickel
Rubber
Topical medications
Characteristics of Pityriasis Rosea
Numerous
Oval
Scaly
Plaques
Follow cleavage lines of the trunk
Begins with initial lesion (“Herald Patch”) larger than later lesions
Characteristics of Psoriasis
Well-circumscribed
Plaques
Silvery scales
Predominantly extensor surfaces & scalp
Characteristics of Seborrheic Dermatitis
Scaly
Oily
Erythematous rash
Skinfolds around: Nose Eyebrows Ears Scalp
Characteristics of Seborrheic Keratosis
Benign
Pigmented
Well-demarcated border
Velvety / Greasy surface
“Stuck On” appearance
Mongolian Spot
Benign
Flat
Blue-grey patches
Usually over lower back & buttocks
Can be seen elsewhere
Look like bruises, but are nontender. Document them so future providers know.
Nonwhite children have them at birth, spontaneously fades during first decade. So benign. Reassure.
When does colic (prolonged periods of inconsolable crying) peak?
2 months
Parents get exhausted, increases risk of abuse
Cafe-au-lait macules are associated with
Neurofibromatosis
Ash-leaf spots are associated with
Tuberous Sclerosis
Port-wine stains are associated with
Sturge-Weber syndrome
Cafe-au-lait macules
Ash-leaf spots
Port-wine stains
These skin findings make you want to look for
Intracranial lesions
Epilepsy
They are all associated with neurocutaneous syndromes
When is Babinski reflex normal?
< 1 year
When are Seborrheic Keratoses not benign?
When several appear all at once, they may indicate occult internal malignancy (Leser-Trelat sign).
Usually, they’re benign AF, though.
Treatment for Seborrheic Keratoses
Observation
If bothersome, excision, cryosurgery or electrodessication may be performed.
Acrochordon
Skin Tag
Seen in regions subjected to friction (neck, axilla, inner thigh)
Most common presentation of Basal Cell Carcinoma
Slow- growing papule or nodule
Pearly, rolled border
Overlying telangiectasias
Ulceration common
Bleeding following minor trauma common
Cutaneous warts
Most common in children & young adults
Seen on hands, elbows & feet
Not usually pigmented
Biopsy findings of Seborrheic Keratosis
So rarely done
Small cells (resembling basal cells)
Variable pigmentation
Hyperkeratosis
Keratin-containing cysts
Differentiating Melanoma from Seborrheic Keratosis
Melanoma has:
Indistinct or irregular border
Smooth or nodular surface
Changing appearance over time
Predilection for sun-exposed areas
Biopsy is occasionally required to tell the difference.
What causes Molluscum Contagiosum?
Poxvirus
Characteristics of Molluscum Contagiosum
Small, pruritic, skin-colored papules
Umbilicated centers
Diagnosis is clinical
Affects mostly children
Adults & adolescents can develop them too
How is Molluscum Contagiosum transmitted?
Skin-to-skin
Contaminated fomites
Autoinoculation to additional sites
Where do Molluscum Contagiosum lesions appear in kids?
Extremities
Face
Trunk
Where do Molluscum Contagiosum lesions appear in adults?
Anogenital region (sexxxxxx)
Molluscum Contagiosum treatment
Self-limited illness (6 - 12 months)
To prevent further spread, reduce symptoms or for cosmetic reasons, you can do:
Curettage
Cryotherapy
Topical agents (podophyllotoxin)
Who has a prolonged course with Molluscum Contagiosum?
Patients with impaired cellular immunity
Poorly controlled HIV patients can have hundreds of lesions.
If Molluscum Contagiosum has excessively large, numerous or widespread lesions, what do you do?
HIV Test
Hypersensitivity rash with blisters or bullae
Type 2 (Antibody-dependent cellular cytotoxicity)
Erythematous maculopapular hypersensitivity rash
Type 3 (Immune complex deposition)
C3 deficiency predisposes you to
Pyogenic bacterial respiratory tract & sinus infections
C5 - C8 deficiency predisposes you to
Recurrent Neisseria infections
Disorders of Phagocytosis
Chronic Granulomatous Disease
Chediak-Higashi
Job Syndrome
Defective leukocyte adhesion proteins)
Present with severe pyogenic bacterial infections
Selective IgA deficiency predisposes you to
Recurrent respiratory infections
Chronic giardiasis
Most common form of Tinea Capitis in the USA
Black Dot Tinea Capitis
Most common in African Americans
Trichophyton Tonsurans is the cause, but other dermatophytes can cause TC as well
Transmission of Tinea Capitis
Human-to-human
Fomites (shared combs)
Characteristics of Tinea Capitis
Scaly, erythematous plaque on the scalp
Progresses to patchy alopecia w/ residual black dot (broken hair)
Other findings: Inflammation Pruritus Occipital or postauricular lymphadenopathy Scarring
Diagnosis of Tinea Capitis
Clinical diagnosis
Can confirm with KOH exam of hair stubs
Treatment of Tinea Capitis
PO Griseofulvin or Terbinaine
Many experts recommend household contacts be treated with Selenium Sulfide or Ketoconazole Shampoo
Alopecia Areata
Smooth circular areas of hair loss
No scaling
Discoid Lupus Erythematosus
Well-demarcated inflammatory plaques Hypo- or Hyperpigmented lesions Scarring Photosensitivity Alopecia
Cutaneous candidiasis
Erythematous
Vesiculopapular rash
Warm, moist areas (Skin folds)
Pressure-induced alopecia
From prolonged pressure on scalp during surgical procedures
Transient hair loss develops a few weeks postop
Regrowth ensues without significant residual alopecia
Hair pattern of trichotillomania
Irregular pattern
Broken hair strands of varying length
Seborrheic Dermatitis of the Scalp
Dandruff
Etiologies of Urticaria
Infections (Viral, bacterial, parasitic)
IgE Mediated (Antibiotics, insect bites, latex, food, blood products)
Direct mast cell activation (Narcotics, muscle relaxers, radiocontrast medium)
NSAIDs
Idiopathic (up to 50% of patients)
Most commonly affected sites for atopic dermatitis in adults
Flexural areas (neck, antecubital, popliteal)
Face
Wrist
Forearms
Timeline of Contact Dermatitis
Symptoms develop over hours-to-days
Symptoms resolve within several days
Erythema Multiforme
Target lesion Erythematous, iris shaped macules Can also contain vesicles or bullae Can be painful or pruritic Symmetrically distributed on extensor surfaces of extremities. Also palms and soles
Etiology of Pityriasis Rosea
Likely viral
Self-limited
Difference between Stevens-Johnson Syndrome & TEN
SJS is when it affects < 10% of body surface area
TEN is when it affects > 30% of body surface area
Anything in between is an overlap
Onset of SJS / TEN
4 - 28 days after exposure to trigger (2 days after repeat exposure)
Acute flu-like prodrome
Rapid onset erythematous macules, vesciles, bullae
Necrosis & sloughing of epidermis
Mucosal involvement
Drug triggers of SJS/TEN
Allopurinol Antibiotics (Sulfonamides) Anticonvulsants (Carbamazepine, Lamotrigine, Phenytoin) NSAIDs (Piroxicam) Sulfasalazine
Non-drug triggers of SJS/TEN
Mycoplasma Pneumoniae
Vaccination
Graft vs. Host Disease
Clinical features of Stevens Johnson Syndrome
Coalescing erythematous macules
Bullae
Desquamation
Mucositis
Systemic signs of Stevens Johnson Syndrome
Fever Tachycardia Hypotension AMS Seizures Coma
When does Erythema Multiforme typically present?
After herpes simplex infection
What causes impetigo?
Staph or strep
What causes Pemphigus Vulgaris?
Autoantibodies to desmosomes
Chronic
Oral lesions appear weeks to months prior to skin lesions
Who is affected by scalded skin syndrome?
Children < 6
Diffuse erythema resembling sunburn
Desquamation of palms & soles
Toxic Shock Syndrome
Eczema Herpeticum
Potential complication of severe atopic dermatitis
Superinfection with herpes simplex
Vesicular eruption on already inflamed skin
Scabies
Small pruritic papules in linear arrangement (burrows)
Web spaces, wrists, ankles, genitals, nipples, waistline
Cradle Cap
Seborheic Dermatitis in infants
First line treatment for atopic dermatitis
Topical emollients
How do you get allergic contact dermatitis on your eyelids?
Low concentrations of nickel in some cosmetics
Hypersensitivity of Allergic Contact Dermatitis
Type IV (Cell-mediated) Hypersensitivity
Common triggers of drug induced acne
Glucocorticoids Androgens Immunomodulators (Azathioprine, EGFR Inhibitors) Anticonvulsants (Phenytoin) Antipsychotics Antituberculous drugs (Isoniazid)
Presentation of drug-induced agne
Monomorphic papules or pustules
Lack of comedones, cysts & nodules
Location & age may be atypical for acne
Management of drug-induced acne
Discontinue offending medication
Standard acne therapy unlikely to be effective
Chloracne
From exposure to halogenated hydrocarbons (occupational exposure to dioxin)
Inflammatory nodules
Large comedones
Affects head, neck, axillae
Rash of disseminated gonococcal infection
Vesiculopapular rash
Tenosynovitis
Migratory polyarthralgias
Most patients febrile
Lesions are mostly on distal extremities and last only a few days
Ugly Duckling Sign
Patient has multiple pigmented lesions
The lesion with a substantially different appearance compared to the others is the ugly duckling
Sensitivity of up to 90% for melanoma
Non ABCDE criteria for concerning skin lesion
Ugly Duckling Sign
Palpable nodularity
Moles that itch or bleed
Most important prognostic indicator in malignant melanoma
Breslow depth
You suspect melanoma in a lesion
Perform excisional biopsy w/ initial margins of 1 - 3mm of normal tissue
Treatment of scabies
Topical 5% permethrin
OR
PO Ivermectin
Hypersensitivity of Scabies rash
Type IV Hypersensitivity to the mite, feces & eggs
What to do when you’ve treated scabies
Bedding & clothing should be cleaned or placed in a plastic bag for >= 3 days.
The mites can’t live away from human skin longer than 3 days
Rash of bed bugs
Small, punctate lesions
Surrounding erythema
Linear tracks or clusters (breakfast, lunch, dinner)
Palms & soles are rare
Who is affected by Bullous pemphigoid?
> 60 years old
Prodrome of eczematous or urticarial lesions
Develop tense bullae & plaques
Affects flexural areas, groin, axilla
Sporotrichosis
Fungal infection by direct traumatic inoculation of the skin
Ulcerating pustular nodules at site of inoculation
Affects associated lymphatic channels
First line treatment of vitiligo
Topical or systemic corticosteroids
Idiopathic Guttate Hypomelanosis
Common with aging
Small macules in sun-exposed areas
Mycobacterium Leprae
Leprosy
Areas of hypopigmentation with anesthesia
Tinea Versicolor
Lightly scaled macules
Chest & upper back
Post-inflammatory hypopigmentation
Piebaldism
Autosomal Dominant
Patchy absence of melanocytes
Usually discovered at birth
Confined to head & trunk
Painful flaccid bullae
Mucosal erosions
Separation of epidermis from dermis by light friction
Pemphigus Vulgaris
Autoimmune attack of Desmogleins 1 & 3 of desmosomes between epidermal keratinocytes
Light microscopy findings of pemphigus vulgaris lesion border
Intraepithelial cleavage
Acantholysis (Detatched keratinocytes)
Single layer of hemidesmosomes in basement membrane (“row of tombstones”)
IgG & C3 deposits in chicken wire pattern
Serology for Abs to Desmoglein 1 & Desmoglein 3 can confirm diagnosis
Risk factors for Squamous Cell Carcinoma of the skin
UV, Ionizing radiation
Immunosuppression
Chronic scars/wounds/burn injuries
Clinical features of Squamous Cell Carcinoma of the skin
Scaly plaques/nodules
+/- Hyperkeratosis or ulceration
Neurologic signs with perineural invasion
Diagnosis of Squamous Cell Carcinoma of the skin
Biopsy: Dysplastic/anaplastic keratinocytes
Biopsy can be punch, shave or excisional, but must include deep reticular dermis to assess depth of invasion.
Suspect Squamous Cell Carcinoma of the skin in patients with
Rough, scaly nodule
Nonhealing, painless ulcer that develops in a scar or chronic inflammatory lesion
Treatment of small or low-risk Squamous Cell Carcinoma lesions of the skin
Surgical excision or local destruction (cryotherapy, electrodessication)
Treatment of high-risk Squamous Cell Carcinoma lesions of the skin
Mohs micrographic surgery (Layered)
Unilateral vesicular hand lesion in patient who has herpes
Herpetic whitlow
Tingling, burning & pain are common
Epitrochlear or axillary lymphadenopathy possible
Dome-shaped
Firm
Freely movable cyst or nodule
Central punctum
Most commonly on face, neck, scalp or trunk
Epidermal Inclusion Cyst
Discrete, benign nodule
Lined with squamous epithelium
Contains semisolid core of keratin & lipid
May remain stable or gradually increase in size
May produce cheesy white discharge
Resolves spontaneously
Excision is usually for cosmesis
When should sunscreen be put on?
15 - 30 minutes before sun exposure
Allows formation of a protective film
How often should sunscreen be reapplied?
Every 2 hours
Also after swimming or sweating, even if it is “water resistant”
Who shouldn’t wear sunscreen?
Babiez < 6 months
Thin skin & high surface area-to-body ratio increases exposure to chemicals.
Use a small amount if sun exposure is unavoidable
Scaly macules & papules
Distributed obliquely along lines of tension
“Christmas Tree” pattern on back
Pityriasis Rosea
Self-limited, spontaneously resolves within weeks-to-months
Symptomatic relief of pruritus = Antihistamines, topical corticosteroids
Erythematous target lesions
Dusky center
Precipitated by infection or medication
Erythema multiforme
Faintly erythematous
Ring-like rash
Comes & goes
Manifestation of acute rheumatic fever
Erythema marginatum
Chronic rash
Dry
Erythematous
Intensely pruritic patches on extremities
Nummular Eczema
Neonate
Asymptomatic scattered erythematous macules, papules & pustules throughout the body
Can change appearance
Occurs in first 2 weeks of life
Erythema Toxcium
Benign. Self-resolves within 2 weeks of life. Reassure.
Neonate
Vesicular clusters on skin, eyes & mucous membranes
Neonatal HSV
Acyclovir
Neonate
CNS infection
Neonatal HSV
Acyclovir
Neonate
Fulminant, disseminated multi-organ disease
Neonatal HSV
Acyclovir
Neonate Fever Irritability Diffuse erythema Blistering & exfoliation Positive nikolsky sign
Scalded Skin Syndrome
Oxacillin
Nafcillin
Vancomycin
Dome-shaped nodules
Central keratinous plug
Keratoacanthomas
Benign
Rare cases have progressed to malignant transformation & metastasis
Slowly enlarging
Mobile
SubQ mass
Soft or ruberry
Lipoma
Rarely malignant. Can observe.
Ring-shaped inflammatory lesion
Peripheral scaling
Tinea corporis
Widespread, scaly eruption of skin
Erythroderma (Exfoliative dermatitis)
May be drug-induced
May be idiopathic
May be 2/2 underlying derm or systemic disease
Discrete Firm Nontender Hyperpigmented nodule <1cm in diameter Dimple in the center when area is pinched
Dermatofibroma
Fibroblast proliferation
Isolated or multiple lesions
Most commonly on lower extremities
Etiology unknown
Some develop after trauma or insect bites
Multicentric
Red, purple or brown
Macules, plaques or nodules
Trunk, extremities or face
Associated with AIDS
Kaposi Sarcoma
Small red papule
Grows rapidly over weeks to months
Becomes pedunculated or sessile shiny mass
Pyogenic granuloma
Occur on lip or oral mucosa
Can bleed with minor trauma
Squamous Cell Carcinoma tends to overly
Ostemomyelitis
Radiotherapy scars
Venous ulcers
Scaly, pruritic patches or plaques
Cutaneous T-Cell Lymphoma
Marjolin Ulcer
Squamous Cell Carcinoma arising within burn wound
Rocky Mountain Spotted Fever
Tick-borne rickettsial illness
Nonspecific signs (Fever, headache, malaise, myalgias)
Diffuse macular rash that turns petichial
Grouped Herpetiform Clusters
Extensor surfaces of elbows, knees, back, buttocks
Dermatitis Herpetiformis
Reaction to gluten
Celiac disease
Biopsy findings in Dermatitis Herpetiformis
Subepidermal microabscesses at tips of dermal papillae
Immunofluorescence: Deposits of anti-epidermal transglutaminase IgA in the dermis
Treatment for Dermatitis Herpetiformis
Dapsone
Gluten-free diet
Treatment for condylomata acuminata
THIS IS HPV
Chemical or physical agents (Trichloroacetic acid, podophyllin)
Immune therapy (Imiquimod)
Surgery (Cryosurgery, excision, laser treatment)
Small papules evenly distributed in a ring around the corona of the glans
Pearly pink penile papules
Benign, non-infectious
Patients often want removal to avoid appearance of an STI
Flattened pink or grey velvety papules
Mucous membranes & moist skin of genitals, perineum and mouth
Condyloma lata
THIS IS FROM Syphilis!
Most common skin cancer in the USA
Basal Cell Carcinoma
Ichthyosis Vulgaris
Chronic Inherited skin disorder Diffuse dermal scaling Mutations in the filaggrin gene Much worse in homozygous patients
Simple emollients first
If those fail, keratolytics (coal tar, sialycylic acid) or topical retinoids may help
Blisters
Bullae
Scarring
Hypopigmentation/hyperpigmentation of sun-exposed skin
Porphyria Cutanea Tarda
Deficiency of uroporphyrinogen decarboxylase necessary for heme synthesis
Conditions associated with Porphyria Cutanea Tarda
Hepatitis C HIV Excessive alcohol Estrogen use Smoking
Diagnosis of Porphyria
Mildly elevated liver enzymes & iron overload
Elevated plasma or urine porphyrin levels
Types of Rosacea
Erythemato-telangiectatic (facial erythema/flushing, telangiectasias)
Papulopustular (Papules & pustules on central face)
Ocular (Conjunctival hyperemia, lid margin telangiectasias)
Treatment of Rosacea
Avoidance of triggers (alcohol, spicy foods)
Sun protection
Gentle cleansers & emollients
Topical metronidazole for papulopustular type
Laser or topical brimonidine for erythematotelangiectatic type
Brimonidine
Vasoconstrictive Alpha-2 Agonist
Who gets erythematotelangiectatic rosacea?
Fair-skinned individuals
> 30 years old
Precipitants of Erythematotelangiectatic Rosacea
Hot drinks
Alcohol
Heat
Emotion
Flushing associated with carcinoid
20 - 30 seconds
Accompanied by hypotension & cyanosis in severe cases
Diarrhea is also seen
Rash of Dermatomyositis
Dusky purple hue:
Eyelids Forehead Neck Chest hands
Photosensitivity is associated with which drugs?
Tetracyclines
Diuretics
Antiemetics
Antipsychotics
Cherry Hemangioma
That thing you see on hella old people
Benign
Strawberry hemangioma
Also called superficial infantile hemangioma
First weeks of life
Initially grow rapidly
Frequently regress by age 5 - 8
If on eyelid, can cause strabismus
If in trachea, can be life-threatening
Beta blockers for patients at risk for complications
Cavernous hemangioma
Cavernous malformation
Dilated vascular spaces with thin-walled endothelial cells
Soft blue compressible masses up to a few cm
Cavernous hemangiomas of the brain & viscera are seen in
Von Hippel-Lindau
Soft Painless Compressible Neck mass Transilluminates
Cystic Hygroma
Benign lymphangioma
Associated with Turner, Down, Edwards, Patau
Blanchable
Pink-red patches
Eyelid, glabella, midline of nape of neck
Nevus Simplex
Present at birth
Fade by age 1 - 2
Neck lesions may persist with no sequellae
How long does it take to transmit lyme disease?
48 hours of tick attachment
When does Erythema migrans manifest?
7 days after infection
Microbe for Tinea Versicolor
Malassezia Furfur
Malassezia Globosa
Budding Yeast on KOH preparation
“Spaghetti & Meatballs” appearance
Malassezia Furfur
Malassezia Globosa
Treatment of Tinea Versicolor
Selenium Sulfide
Ketoconazole
Pigmentation changes may take months to resolve after treatment
Treatment for moderate-to-severe inflammatory acne
Topical Antibiotics:
Erythromycin
Clindamycin
Who mediates Type IV Hypersensitivity?
T Cells!!
What is Acanthosis Nigricans associated with?
Insulin-resistant states:
DM
Obesity
PCOS
Skin tags (acrochordons) are often seen with it
Skin conditions associated with Hepatitis C
Porphyria Cutanea Tarda
Cutaneous Leukocytoclastic Vasculitis (Palpable purpura) 2/2 cryoglobulinemia
Skin conditions associated with Insulin resistance
Acanthosis nigricans
Multiple skin tags
Skin conditions associated with GI Malignancy
Acanthosis nigricans
Excessive onset of multiple itchy seborrheic keratoses
Skin conditions associated with HIV
Severe sudden-onset psoriasis
Recurrent Herpes Zoster
Dissmeinated Molluscum Contagiosum
Severe Seborrheic Dermatitis
Skin conditions associated with Parkinson’s
Severe seborrheic dermatitis
Skin conditions associated with Inflammatory Bowel Disease
Pyoderma gangrenosum
Lentigo
Those dark spots on old people’s faces
Intraepidermal melanocyte hyperplasia
Baby with eczema has localized vesicular rash, not diffusely spread around
HSV 1
Give acyclovir IV
First line treatment for bullous pemphigoid
High-potency topical glucocorticoid (clobetasol)
Most common malignancy of the lip
Squamous cell carcinoma
Biopsy findings of Squamous Cell Carcinoma
Invasive cords of squamous cells with keratin pearls
