Acute Inflammatory Dermatoses

Question 1

understand the hist-pathologic characteristics of acute inflammatory dermatoses

Answer 1

a

Question 2

recognize and describe angioedema

Answer 2

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

Question 3

differentiate Stevens Johnson Syndrome and Toxic Epidermal Necrolysis

Answer 3

a

Question 4

recognize and describe fixed drug eruptions

Answer 4

a

Question 5

recognize and describe panniculitis

Answer 5

a

Question 6

erythema nodosum

Answer 6

a

Question 7

erythema induratum

Answer 7

a

Question 8

locations of:

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

Answer 8

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

Question 9

Urticaria

Answer 9

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

Question 10

Urticaria and Angioedema Clues

Answer 10

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

Question 11

urticaria vs angioedema

Answer 11

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

Question 12

Urticaria and AngioedemaCauses

Answer 12

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

Question 13

Urticaria and Angioedema:Causes: Immune

Answer 13

. 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.

Question 14

Urticaria and Angioedema:Causes: Non-immune

Answer 14

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

Question 15

Physical Urticarias (Non-immune)

Answer 15

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

Question 16

Direct Mast Cell Degranulation (Non-Immune)

Answer 16

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

Question 17

Foods Containing High Levels of Histamine (Non-Immune)

Answer 17

Strawberries
Tomatoes
Shrimp
Lobster
Cheese
Spinach
Eggplant

Question 18

Urticaria and AngioedemaLaboratory Evaluation

Answer 18

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

Question 19

Urticaria and AngioedemaTherapy

Answer 19

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.

Question 20

Erythema Multiforme

Answer 20

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.

Question 21

Erythema MultiformeTherapy

Answer 21

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

Question 22

Stevens Johnson Syndrome

Answer 22

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

Question 23

Differentiation

Answer 23

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)

Question 24

SJS/TEN Epidemiology

Answer 24

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

Question 25

SJS/TEN Etiology

Answer 25

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

Question 26

Toxic epidermal necrolysis (TEN)

Answer 26

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)

Question 27

SJS/TEN Therapy

Answer 27

``` 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 ```

Question 28

Fixed Drug Eruption

Answer 28

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.

Question 29

Panniculitis

Answer 29

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

Question 30

Panniculitis Erythema Nodosum

Answer 30

``` 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 ```

Question 31

Panniculitis Erythema Induratum

Answer 31

``` 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 ```