Acute Inflammatory Dermatoses Flashcards Preview

SMS Week 3 > Acute Inflammatory Dermatoses > Flashcards

Flashcards in Acute Inflammatory Dermatoses Deck (31):
1

understand the hist-pathologic characteristics of acute inflammatory dermatoses

a

2

recognize and describe angioedema

Deep dermal and Subcutaneous swelling
Burning/Painful
Laryngeal Involvement = Emergency

3

differentiate Stevens Johnson Syndrome and Toxic Epidermal Necrolysis

a

4

recognize and describe fixed drug eruptions

a

5

recognize and describe panniculitis

a

6

erythema nodosum

a

7

erythema induratum

a

8

locations of:

Urticaria:
Erythema Multiforme:
SJS/TEN:
Fixed Drug Eruption
Panniculitis:

Urticaria: Dermis
Erythema Multiforme: Epi/Dermis
SJS/TEN: Epi/Dermis
Fixed Drug Eruption Epidermis
Panniculitis: Subcut
Erythema Nodosum
Erythema Induratum

9

Urticaria

dermal edema, usually result of oral allergy
Transient Wheals
Persist for <24 hours (for any given wheal)
IgE and histamine mediated
Pruritic
Ask about new exposures/medications

Angioedema (severe form):
Deep dermal and Subcutaneous swelling
Burning/Painful
Laryngeal Involvement = Emergency

10

Urticaria and Angioedema Clues

Each patient needs a thorough history that details travel, recent infection, occupational exposure, meds (Rx and OTC), ingestion of foods, and any exposure to physical stimuli.
Careful family history documenting pre-existing allergies.
Comprehensive physical exam looking carefully at all skin surfaces, joints, conjunctiva and mucosal membranes.
Prevalence: 14-25% in US

11

urticaria vs angioedema

Urticaria:
Pruritic
Transient raised wheals
Less than 24 hours
Pathology: dermal edema
+/- eosinophils/lymphs/pmns


Angioedema
Intense swelling of the dermis and SQ
Painful>pruritic
Lip, eye, groin, palms/soles common
Laryngeal involvement = Emergency

12

Urticaria and Angioedema Causes

I Immune
A. Type I IgE Mediated
B. Auto-immune
C. Infectious
II Non-Immune
A. Physical Urticarias
B. Direct mast-cell degranulation
C. Foods containing high levels of histamine

13

Urticaria and Angioedema: Causes: Immune

. Type 1 IgE mediated
Foods: shellfish*, fish*, peanuts*, tree nuts*, eggs, milk, soy, wheat. (* seen in adults) (seen in kids)
Latex
Stinging insects including hymenoptera (bees, wasps, hornets), fire ants, bedbugs, fleas, mites.
Medications: penicillin, cephalosporin, sulfa
Aeroallergens: dust mites, pollens, molds, animal dander

B. Autoimmune disease: Hashimoto’s immune thyroiditis (production of anti-thyroid antibodies), SLE, vasculitis.
(there may be thyroid anti-autobodies in the absence of thyroid dysfunction)

C. Infection: viral (cytomegalovirus, Epstein-Barr, HIV, hepatitis A, B & C); parasitic, fungal or bacterial.

14

Urticaria and Angioedema: Causes: Non-immune

Non-immune (no Ag-AB reaction; no prior sensitization needed; can happen with first exposure)
A. Physical urticaria
B. Direct mast cell de-granulation
C. Foods containing high levels of histamine

15

Physical Urticarias (Non-immune)

Solar (sun)
Cholinergic (sweating vs heat)
Cold urticaria
Dermographism (friction)
Aquagenic (water)
Vibratory angioedema
Pressure urticaria (burning hands, feet, butt)

16

Direct Mast Cell Degranulation (Non-Immune)

Narcotics (MS and codeine)
Aspirin
NSAIDs
Radiocontrast media
Dextran
ACE inhibitor angioedema
Vancomycin - “Red Man” syndrome See flushing with hives after IV vancomycin

17

Foods Containing High Levels of Histamine (Non-Immune)

Strawberries
Tomatoes
Shrimp
Lobster
Cheese
Spinach
Eggplant

18

Urticaria and Angioedema Laboratory Evaluation

Rule 1: don’t get carried away! Expensive lab evaluations usually have poor yields.

Basic evaluation includes CBC, ESR, TSH, and a basic chemistry panel

Consider throat culture, monospot if warranted by history

Check anti-thyroid antibody titer and FANA on female patients.

Punch biopsy to exclude vasculitis if lesion persists > 48 hrs or looks atypical

19

Urticaria and Angioedema Therapy

General measures: avoid allergen, avoid extremes of heat and cold, exercise, and alcohol (vasodilatation, flares, hives).

Acute urticarial hallmark of Rx is antihistamines, preferably non-sedating H1 blockers.

Chronic urticarial patients get frustrated! Cause of urticaria not found in 75-80%, but most improve slowly over 1-2 years.

20

Erythema Multiforme

Reaction Pattern of blood vessels in the dermis
Secondary epidermal changes manifest clinically as erythematous iris-shaped papular and veisculobullous lesions
Involving extremities (especially palms and soles) and mucous membranes
Epidemiology: 50% are under 20 years and more frequent in males
Etiology: Cutaneous reaction to a variety of antigenic stimula (drugs vs infection vs idiopathic)
Drugs: Sulfonamides, phenytoin, barbiturates, phenylbutazone, penicillin, allopurinol
Infection: Herpes Simplex Virus, Mycoplasma
Idiopathic: more than 50%
Acute hypersensitivity reaction showing classic “target” lesions.
EM minor = mild form involving ≤ 1 mucosal site; major cause is post herpes simplex infections with onset of EM rash at day 10.
EM major = severe with extensive skin and mucous membrane involvement (Stevens-Johnson Syndrome). Usually due to drugs (sulfa, PCN, dilantin, tegretol) and after mycoplasma pneumoniae infection.

21

Erythema Multiforme Therapy

Prevention: Control Herpes Simplex using Rx
Glucocorticoids: For severe ill-systemic prednisone
Supportive
Can differentiate EM from hives in that EM is fixed and usually does not itch

22

Stevens Johnson Syndrome

Toxic Epidermal Necrolysis
Mucocutaneous Drug-Induced or Idiopathic Reaction Patterns
Skin Tenderness and Erythema of Skin and Mucosa
Followed by Extensive Cutaneous and Mucosa Epidermal Necrosis and Sloughing
Potentially Life Threatening

23

Differentiation

Erythema Multiforme (1 mucosal membrane)

Stevens-Johnson Syndrome (SJS): Considered a Maximal Variant of EM Major (2+ mucosal membrane and < 10% epidermal detachment)

SJS/TEN overlap (10-30% epidermal detachment)

Toxic Epidermal Necrolysis (TEN): Maximal Variant of SJS (2+ mucosal membrane and 30% epidermal detachment)

24

SJS/TEN Epidemiology

Age: any age, but most common >40 years
Equal sex incidence
Overall incidence: SJS: 1.2-6 per million population per year and TEN: 0.4-1.2 per million population per year
Risk Factors: Systemic Lupus Erythematosis, HLA-B12, HIV Disease

25

SJS/TEN Etiology

Drugs are the leading causative factor
SJS: 50% associated with Rx often not clear
TEN: 80% strong association with Rx
Cytotoxic immune reaction aimed at destruction of keratinocytes expressing foreign (drug-related) antigens
Time from first drug exposure to symptoms is 1-3 weeks

26

Toxic epidermal necrolysis (TEN)

it is unclear whether TEN is a severe form of erythema multiforme or a distinct disease

80% of cases have a strong association with a specific drug (list is similar to that for erythema multiforme)

TEN is a medical emergency, on the order of a total body burn

A severe hypersensitivity syndrome, life threatening
Begins within hours to days of exposure (up to 2 wks) with fever, malaise, arthralgias
Painful morbilliform rash develops during 1st wk, then becomes confluent, then bullous and exfoliative
Total detachment of epidermis (total body 2nd degree burn)

27

SJS/TEN Therapy

Early Diagnosis and Withdrawal of Rx
ICU
Management of IV Fluids/Electrolytes
Systemic Glucocorticoids Early?
High Dose Immunoglobulins for TEN
Debride only frankly necrotic skin
Treat complications
Mortality Rate for SJS 5% and for TEN 30%
Mortality related to sepsis, GI hemorrhage and fluid/electrolyte imbalance

28

Fixed Drug Eruption

Definition: a localized, sharply demarcated erythematous patch that can itch, burn or be asymptomatic.
Predisposition for face and genitals.
Often heals as a hyperpigmented area.
Pseudoephedrine is non-pigmenting
Will recur in the same place if rechallenged
Unknown mechanism but felt to be immune.
Therapy: eliminate the offending drug.

29

Panniculitis

Major focus of inflammation: subcutaneous tissue
Erythematous or violaceous nodule in the SQ fat
Described as lobular or septal depending on where disease process begins
Accurate diagnosis by skin biopsy

30

Panniculitis Erythema Nodosum

Erythematous tender nodules
Septal panniculitis
Typically ANTERIOR shins
Young women most common
Triggers
Infection (strep, TB, fungal)
Meds (OCP, Sulfa, NSAIDS)
Autoimmune (IBD, Sarcoid)
Treatment: rest, ice, pain control

31

Panniculitis Erythema Induratum

Tender red nodules
Lobular panniculitis and vasculitis
Middle aged, usually female
Posterior legs>ant
Chronic, recurrent subcutaneous nodules and plaques with ulceration
Associated with TB