Dermatology

Question 1

Pemphigus Vulgaris

Answer 1

autoimmune of unclear etiology in which body becomes allergic to owen skin

• antibodies are produced against anigens in the intercellular spaces of epidermal cells
• bullae are within epidermis and are thin and fragile
• painful bullae but not pruritic

Question 2

Causes of Pemphigus Vulgaris

Answer 2

• Idiopathic
• ACE inhibitors
• Penicillamine

Question 3

Nikolsky’s sign

Answer 3

easy removal of skin by just a little pressure with the examiner’s finger pulling it off like a sheet

Question 4

Diseases where Nikolsky’s sign is present

Answer 4

• Pemphigus vulgaris
• Staphylococcus scalded skin syndrome
• Toxic epidermal necrolysis

Question 5

Pemphigus Vulgaris: Dx

Answer 5

skin biopsy

Question 6

Pemphigus Vulgaris: Tx

Answer 6

• use glucocorticoids, such as prednisone
• when steroids are ineffective, use the following:
  azathiaprine
  mycophenolate
  cyclophosphamide

Question 7

Bullous pemphigoid

Answer 7

• can be drug induced by sulfa drugs and others
• fracture of skin is realtively deep and bullae are THICKER WALLED and LESS LIKELY TO RUPTURE
• oral lesions are rare
• less fluid loss and infection less likely

Question 8

Bullous pemphigoid: dx

Answer 8

• perform a biopsy with immunofluorescent antibodies

Question 9

Bullous pemphigoid: tx

Answer 9

• Use systemic steroids such as prednisone
• Alternatives to steroids
  
  • tetracycline
  • erythomycin with nicotinamide

Question 10

Pemphigus foliaceus

Answer 10

• associated with other autoimmune diseases
• can be drug induced from ACE inhibitors or NSAIDs
• bullae are more superficial than pemphigus vulgaris
• intact bullae rarely seen because they are so fragile
• no oral lesions

Question 11

Pemphigus foliaceus: dx and tx

Answer 11

- diagnosed by biopsy and treated with steroids 
Alternatives to steroids
- mycophenolate
- cyclophosphamide
- azathioprine

Question 12

Porphyria Cutanea Tarda (PCT)

Answer 12

• disorder of porphyrin metabolism resulting in photosensitivity reaction to an abnormally high accumulaition of porphyrins

Question 13

Conditions associated with Porphyria Cutanea Tardia

Answer 13

• Alcholism
• Chronic hep C
• Liver disease
• Oral contraceptives
• Liver diease is associated with increased liver iron stores
• Diabetes are found in 25% of these patients

Question 14

Porphyria Cutanea Tarda: Clinical presentation

Answer 14

• Nonhealing blisters on sun exposed parts of the body such as backs of hands and the face
• Hyperpigmentation of the skin
• Hypertrichosis of the face

Question 15

Porphyria Cutanea Tarda: Diagnostic Testing

Answer 15

Test for urinary uroporphyrins

- uroporphyrins are elevated 2-5 times above coporyphyrins in this disease

Question 16

Porphyria Cutanea Tarda: Tx

Answer 16

• Stop drinking alcohol
• Stop all estrogen use
• Use barrier sun protection
• Use phlebotomy to remove Fe. Deferoxamine used to remove Fe
• Chloroquine increases the excretion of porphyrins

Question 17

Urticaria

Answer 17

• hypersensitive reaction, most often mediated by IgE and mast cell activation, which in EVANESCENT WHEALS AND HIVES
• localized with hypotension and hemodynamically instability
• onset within 30 minutes and last < 24 hrs
• itching is prominent

Question 18

Causes of urticaria

Answer 18

• Meds (aspirin, NSAIDS, morphine, codene, penicilline, phenytoin)
• Insect bites
• Foods (peanuts, shellfish, tomatoes, and strawberries)
• Emotions
• Contact with latex

Question 19

Chronic urticaria is associated with the following:

Answer 19

• Pressure on skin (e.g. dermatographism)
• Cold
• Vibration

Question 20

Severe acute urticaria: tx

Answer 20

H1 antihistamines (e.g. diphenhydramine, hydroxyzine, cyproheptatine

Question 21

Acute urticaria that is life threatening: tx

Answer 21

H1 antihistamines + systemic steroids

Question 22

Chronic urticaria tx

Answer 22

Newer antihistamines

• loratadine
• desloratadine
• fexofenadine
• certirizine

Question 23

If patient develops urticaria due to trigger that can’t be avoided, what’s long term solution?

Answer 23

Desensitization

** make sure to stop B-blockers because they inhibit the epinepherine

Question 24

Morbilliform rashes

Answer 24

• milder form of urticaria
• typical type of drug reaction
• rash RESEMBLES MEASURES; it is GENERALIZED MACULOPAPULAR ERUPTION THAT BLANCHES WITH PRESSURE
• can appear a few days after initial exposure

Question 25

Morbilliform rashes: dx and tx

Answer 25

- Lymphocyte mediated | - teat with antihistamines

Question 26

Erythema Multiform Causes

Answer 26

``` - caused by: penicillins phenytoins NSAIDS Sulfa drus Infection with Herpes Simplex or Mycoplasma ```

Question 27

Erythema Multiforme

Answer 27

- presents with TARGETLIKE LESION that occurs on palms and soles - lesions can be described as "irislike" - bullae not unformly found - does not involve mucous membranes

Question 28

Erythema Multiforme: Tx

Answer 28

Antihistamines and treat the underlying infection

Question 29

Stevens-Johnson Syndrome

Answer 29

- hypersensitivity rxn to meds (e.g. penicillins, sulfa drugs, NSAIDS, phenytoin, and phenobarbitol) - usually involves 10 - 15 % of total body surface area - has mucous membrane involvement - respiratory tract involvement may be so severe as to require mechanical ventilation - should be managed in burn unit

Question 30

Mortality and morbidity associated with Stevens-Johnson Syndrome

Answer 30

- infection, dehydration, and malnutrition

Question 31

Stevens-Johnson Syndrome: Tx

Answer 31

Supportive therapy

Question 32

Toxic Epidermal Necrolysis

Answer 32

- most serious version of cutaneous hypersensitivt reaction - covers 30 - 100% of body surface area - sepsis is most common cause - Nikolsky sign is present and skin easily sloughs off

Question 33

Toxic Epidermal Necrolysis: Dx

Answer 33

Skin biopsy | ** don't use steroids

Question 34

Fixed Drug Reaction

Answer 34

- localized allergic drug reaction that occurs at precisely the same anatomic site with repeated drug exposure - lesions are ROUND, SHARPLY DEMARCATD LESIONS THAT LEAVE HYPERPIGMENTED SPOT AT THE SITE

Question 35

Fixed Drug Rxn: Tx

Answer 35

Topical steroids

Question 36

Erythema Nodosum

Answer 36

- painful, red, raised nodules appear on anterior surface of extremities - nodules are tender to palpation - nodules do not ulcerate - nodules last about 6 weeks

Question 37

Erythema Nodosum associated with which conditions:

Answer 37

``` secondary to recent infections or inlammatory condtiions such as: - Pregnancy - Recent strep infxn - Coccidiodomycoses - Histoplasmosis - Sarcoidosis = Inflammatory bowel disease - Syphilis - Hepatitis - Enteric infection (e.g. Yersinia) ```

Question 38

Erythema Nodosum: Tx

Answer 38

- Analgesics and NSAIDS and treat the underlying disease | - if symptomatic treatment fails, potassium iodide

Question 39

``` Suspected fungal infxn : diagnostis - tinea pedis - tinea cruris - tinea corporis - tinea versiclor - tinea capris - ```

Answer 39

1. Perform KOHtest of skin. KOH can dissolve some epithelail cells and collage of the nail but doesn't melt away fungus 2. Most accurate test: culture of fungus

Question 40

Onychomycosis (nail fungal infection) : tx

Answer 40

Oral terbinafine or itraconazole - 6 weeks for fingernails - 12 weeks for toes

Question 41

Hair fungal infection (tinea capitus)

Answer 41

Oral terbinafine or itraconazole

Question 42

Terbinafine

Answer 42

- used to treat skin and hair fungal infections - potentially hepatotoxic - check liver function tests periodically

Question 43

Adverse effects of ketaconazole

Answer 43

- Hepatotoxicity - Gynecomastia * * don't use for onychomycosis**

Question 44

Impetigo

Answer 44

- special bacterilal infection of skin limited to largely epidermis - infection is described as "weeping" "oozing" "honey-colored" or draining" - found in warm, humid conditions - seen in poverty and in children - can cause glomerulonephritis but no rheumatic fever

Question 45

Impetigo: etilogy

Answer 45

Staphylococcus | - can be caused by Streptococcus pyogenes (aka Group A Strep_)

Question 46

Impetigo: Tx

Answer 46

- Any topical abx: mupirocin | - If topical abx not effective, antistaphyloccocus oral abx

Question 47

Erysipelas

Answer 47

- involves both dermis and epiderms - most commonly caused by Group A Strep (pyogenes) - most likely bacterial infxn to lead to fevers, chills, and bacteremia - bright, red, angry, swollen appearance in face

Question 48

Erysipelas: tx

Answer 48

= use systemic oral or IV abx | - if there is culture confirmation of the organism as Streptococcus then penicillin G or ampicillin

Question 49

Cellulitis

Answer 49

- bacterial infection of dermis and subcutaneous with Stap and Strep