Derm

Question 1

What is pemphigus vulgaris?

Answer 1

Middle aged patient

Due to autoantibodies (igG or complement C3) against desmoglein 3 & 1 (desimosomes)

(+) Nikolsky sign (thin blisters that break easily)

Involvement of oral mucosa

Epidermis breaks- Basement membrane is intact

Question 2

What is pemphigus pemphigoid?

Answer 2

Older patient

Due to autoantibodies against hemidesmosomes

No involvement of oral mucosa

(-) Nikolsky sign

epidermis lifts off the basement membrane

Question 3

What is dermatitis herpetiformis?

Answer 3

Cutaneous manifestation of gluten sensitivity (celiac dz)- if not already diagnosed w/ celiac get dz confirmation w/ antibody screening (anti-TTG) and duodenal biopsy

Neutrophilic abscesses (IgA deposits) in the dermal papillae

Itchy bumps on extensor surfaces and buttocks

Definitive Tx by removing gluten from diet

Temporary relieve symptoms w/ treated with dapsone or sulfapyridine

Question 4

What is tinea versicolor?

Answer 4

Scaly hypoigmented macules/ patches

Caused by Malassezia globosa

treat w/ topical antifungals such as selenium sulfide shampoo or ketoconazole

Question 5

What is atopic dermatitis (eczema)?

Answer 5

Atopic dermatitis, like its associated asthma, can be triggered/ worsened by triggers such as stress or environmental allergens.

defect in stratum corneum–> extreme pruritis–> lichenification (leathery skin)

Tx w/ topical steroids for inflammation and emollients for healing

Can also give antihistamine for itching relief

oral steroids and UV light therapy only for refractory cases

Question 6

How to diagnose melanoma?

Answer 6

For mole w/ high melanoma suspicion–> Wide Excisional biopsy

For mole w/ low melanoma suspicion–> punch biopsy

Question 7

What is porphyria cutanea tarda?

Answer 7

Presents in middle age with fragile hemorrhagic bullae on the backs of the hands and hypertrichosis on the tops of the cheeks.

Increased levels of uroporphyrins and coprporphyrins, causing the urine to have a reddish color and fluoresce under Wood’s lamp

brought on by hormones (think OCPs), alcohol, and hepatitis C and worsened during periods of stress

Question 8

What is an ash leaf spot?

Answer 8

Hypopigmented macule, often found on the trunk or extremities, enhanced by UV light (Wood’s lamp)

Associated with tuberous sclerosis (TS)

Need to do MRI for brain tumor when pt presents w/ ash leaf spot

Also get a MRI of the abdomen, an echocardiogram of the heart, and, if indicated, an electroencephalogram to look for seizure activity.

Question 9

What is the treatment for tinea corporis?

Answer 9

Pruritic, erythematous, raised and scaly annular (circular) patch with central clearing

Even “classic” presentations of tinea corporis should have diagnosis confirmed with skin scraping and subsequent KOH microscopy to reveal fungal hyphae.

First-line treatment is with topical antifungals Ketoconazole

Question 10

What is allergic contact dermatitis (poison ivy)?

Answer 10

Contact with poison ivy causes an allergic contact dermatitis, a type IV hypersensitivity reaction.

Question 11

Examples of type II hypersensitivity reactions?

Answer 11

Type II hypersensitivity reactions occur when antibodies are formed that target antigens on the surface of cells or tissues. Examples include grave’s disease, myasthenia gravis, and ABO incompatibility.

Question 12

Examples of type III hypersensitivity reactions?

Answer 12

Type III hypersensitivity reactions are caused by antigen-antibody complexes that deposit in tissues and cause an immune response. Examples include rheumatoid arthritis, systemic lupus erythematosus, and reactive arthritis

Question 13

What is Stevens-Johnson syndrome?

Answer 13

Stevens-Johnson syndrome (<10% of the body) and Toxic Epidermal Necrolysis (>30% of the body) comprise each end on a spectrum of the same disease.

These patients will have widespread loss of sheets of skin, a positive Nikolsky’s sign, and will be toxic—even critically ill. Most of the cases when a cause is identified evolve as an extreme drug reaction

Question 14

What is the treatment for scabies?

Answer 14

Scabies infection often presents as the “worst itch of my life” and classically involves the hands, elbows, and male genitalia.

If not clear from the exam, microscopic evaluation of a skin scraping should reveal the mite.

Treatment includes both topical permethrin and sterilization of laundry.

Question 15

What is the treatment for acne?

Answer 15

Begin with topical retinoids for mild noninflammatory acne (open and closed comedones)

Add benzoyl peroxide in the setting of more inflamed comodones and pustules

if incomplete improvement, adding topical antibiotics

Severe, treatment-resistant acne which may already have scarring, warrants cessation of other therapies and initiation of oral isotretinoin

Question 16

What is a morbilliform eruption?

Answer 16

Drug eruptions, outside of anaphylaxis, do not occur immediately.

Typical onset for morbilliform eruptions if 7-14 days after the first exposure to offending drug

Question 17

What is Stevens-Johnson syndrome?

Answer 17

Stevens-Johnson syndrome presents as dusky, irregular, flat, purpuric maculae

It affects less than 10% of the total body surface area.

frequently involves the trunk, oral mucosa and the conjunctivae of the eyes

Question 18

What drugs/infections are associated w/ Stevens-Johnson syndrome?

Answer 18

Associated w/ sulfonamides, penicillin, and phenytoin (drugs)

Herpes simplex and Mycoplasma (infections).

Question 19

What is erythema multiforme?

Answer 19

EM is an immune complex mediated hypersensitivity reaction (type IV)

Erythematous target-shaped macules with dusky/purple centers at acral sites (such the palms, fingers and ears)

EM is most commonly triggered by infections (Herpes simplex virus and Mycoplasma)
and certain drugs (cephalosporins)

Question 20

How does tinea captitis present?

Answer 20

Fungal infection that can cause patchy alopecia in multiple well-circumscribed areas

Confirm the diagnosis with a KOH prep of skin scrapings before treating w/ ORAL antifungal (griseofulvin)

Question 21

What is Pityriasis rosea?

Answer 21

Nonscaly pink rash—the herald patch—that transforms into scales, sparing the palms and soles

No treatment- self limited

There is no test to confirm pityriasis but rule out serious other dz that have similar rash such as secondary syphilis w/ RPR

Question 22

Diagnosis of dermatomyositis

Answer 22

proximal muscle weakness and skin manifestations

Muscle biopsy is required for diagnosis

creatine kinase and aldolase will be elevated

Question 23

Hypomagnesemia symptoms

Answer 23

Hypomagnesemia may be caused by upper or lower gastrointestinal loses.

A history of vomiting or diarrhea is key to the diagnosis.

Question 24

Grover disease (transient acantholytic dermatosis)

Answer 24

benign, self-limited itchy papular rash over the trunk

may be triggered by excessive sweating, heat, humidity, and sun exposure

Question 25

Familial benign pemphigus (i.e. Hailey-Hailey disease)

Answer 25

Vesicular lesions and crusting erythematous plaques over the genital area, as well as the chest, neck, and axilla

Burning and pruritus, malodorous drainage

These pts also have multiple asymptomatic longitudinal white bands on the fingernails (unknown why)

Question 26

Treatment for postherpetic neuralgia

Answer 26

Postherpetic neuralgia (PHN) is a complication of herpes zoster

Nortriptyline has been considered the mainstay of therapy although gabapentinoids are the only FDA approved medications for PHN

Question 27

Corrected calcium based on albumin level

Answer 27

Corrected calcium = ((4 - albumin) x 0.8) + measured calcium

Question 28

What causes Familial benign pemphigus (i.e. Hailey-Hailey disease)?

Answer 28

Autosomal dominant disease due to a mutation in ATP2C1, a calcium ATPase pump.

Question 29

Dermatologic manifestation of Graves disease

Answer 29

Infiltrative ophthalmopathy (proptosis) and infiltrative dermopathy (pretibial myxedema) are characteristic of Graves’ disease but no other causes of hyperthyroidism

Question 30

amaurosis fugax

Answer 30

transient monocular vision loss- “curtain coming down”

Most commonly due to atherosclerotic disease in the ipsilateral carotid

Requiring a workup for carotid stenosis

Question 31

Treatment for a nondisplaced scaphoid fracture

Answer 31

Thumb spica cast.

Immobilization is important to prevent avascular necrosis and carpal instability.

Question 32

When is Percutaneous screw fixation used for scaphoid fractures?

Answer 32

Minimally displaced fracture without angulation and proximal pole fractures

Question 33

When is Open reduction used for scaphoid fracture?

Answer 33

Significantly displaced/comminuted fractures, associated perilunate dislocation

Question 34

When is Bone grafting and fixation used for scaphoid injury?

Answer 34

Non-union fracture

Question 35

First-line treatment for bullous pemphigoid

Answer 35

High-potency topical corticosteroids, such as clobetasol and halobetasol

Question 36

Von Recklinghausen disease/neurofibromatosis type 1

Answer 36

cafe au lait spots, neurofibromas, freckling in the axillary or inguinal area, and iris hamartomas

scoliosis, spinal deformity, and congenital tibial dysplasia

seizures, mental retardation, or learning disabilities

Question 37

Staphylococcal scalded skin syndrome (SSSS)

Answer 37

Age < 6 years

Presents with the widespread formation of easily ruptured fluid-filled blisters 24-48 hours after the development of fever and irritability.

No mucosal involvement
No targetoid lesions
Nikolsky Sign Positive

Question 38

Toxic epidermal necrolysis (TEN)

Answer 38

> 30% of the body surface area is involved

Mucosal involvement
Nikolsky Sign Positive
Targetoid lesions/ dusky red/purple macules

Question 39

Stevens-Johnson Syndrome (SJS)

Answer 39

Mucosal membranes must be involved or severe conjunctivitis

Nikolsky Sign Positive
Targetoid lesions

Question 40

Drug reaction with eosinophilia and systemic symptoms (DRESS)

Answer 40

Delayed (Type IV) hypersensitivity reaction

Reaction to the drug occurs 1 week to 2 months following the initial administration

occurs after sulfa antibiotics, antiepileptic medications, or allopurinol

Rash is very itchy and morbilliform, rather than bullous