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Flashcards in Dermatology Deck (49):
1

Pemphigus Vulgaris

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

2

Causes of Pemphigus Vulgaris

- Idiopathic
- ACE inhibitors
- Penicillamine

3

Nikolsky's sign

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

4

Diseases where Nikolsky's sign is present

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

5

Pemphigus Vulgaris: Dx

skin biopsy

6

Pemphigus Vulgaris: Tx

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

7

Bullous pemphigoid

- 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

8

Bullous pemphigoid: dx

- perform a biopsy with immunofluorescent antibodies

9

Bullous pemphigoid: tx

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

10

Pemphigus foliaceus

- 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

11

Pemphigus foliaceus: dx and tx

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

12

Porphyria Cutanea Tarda (PCT)

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

13

Conditions associated with Porphyria Cutanea Tardia

- 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

14

Porphyria Cutanea Tarda: Clinical presentation

- 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

15

Porphyria Cutanea Tarda: Diagnostic Testing

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

16

Porphyria Cutanea Tarda: Tx

- 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

17

Urticaria

- 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

18

Causes of urticaria

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

19

Chronic urticaria is associated with the following:

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

20

Severe acute urticaria: tx

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

21

Acute urticaria that is life threatening: tx

H1 antihistamines + systemic steroids

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Chronic urticaria tx

Newer antihistamines
- loratadine
- desloratadine
- fexofenadine
- certirizine

23

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

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

24

Morbilliform rashes

- 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

25

Morbilliform rashes: dx and tx

- Lymphocyte mediated
- teat with antihistamines

26

Erythema Multiform Causes

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

27

Erythema Multiforme

- 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

28

Erythema Multiforme: Tx

Antihistamines and treat the underlying infection

29

Stevens-Johnson Syndrome

- 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

30

Mortality and morbidity associated with Stevens-Johnson Syndrome

- infection, dehydration, and malnutrition

31

Stevens-Johnson Syndrome: Tx

Supportive therapy

32

Toxic Epidermal Necrolysis

- 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

33

Toxic Epidermal Necrolysis: Dx

Skin biopsy
** don't use steroids

34

Fixed Drug Reaction

- 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

35

Fixed Drug Rxn: Tx

Topical steroids

36

Erythema Nodosum

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

37

Erythema Nodosum associated with which conditions:

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)

38

Erythema Nodosum: Tx

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

39

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

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

40

Onychomycosis (nail fungal infection) : tx

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

41

Hair fungal infection (tinea capitus)

Oral terbinafine or itraconazole

42

Terbinafine

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

43

Adverse effects of ketaconazole

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

44

Impetigo

- 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

45

Impetigo: etilogy

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

46

Impetigo: Tx

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

47

Erysipelas

- 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

48

Erysipelas: tx

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

49

Cellulitis

- bacterial infection of dermis and subcutaneous with Stap and Strep