Rhinitis/Uticaria/Drug Rxns MLS

rhinitis

inflammation of the nasal mucosa

what are the causes of rhinitis?

Infectious-

Bacterial

Viral

Meds

Hormonal

Foods

what are allergen antigens that cause allergic rhinitis?

Seasonal

Spring: flowering shrubs and tree pollens

Summer: flowering plants and grasses

Fall: ragweed and mold

Perennial (Chronic)

Pet dander

Dust mites

Indoor mold

pathophysiology of allergic rhinitis

Type I hypersensitivity reaction

what are the 3 phases of allergic rhinitis?

sensitization phase, early phase allergic response, late-phase reaction

sensitization phase

First contact with a specific allergen: IgE antibody forms and binds to mast cells and basophils

early phase allergic response

Subsequent exposure to antigen: binds to the IgE antibody receptor on the mast cell → stimulates mast cell degranulation

late phase reaction

Chemotaxis of inflammatory cells occurs which triggers a second wave of mediator release

what are symptoms of allergic rhinitis?

Episodic clear rhinorrhea

Sneezing

Lacrimation

Congestion

Pruritus

Cough

what are exam findings of allergic rhinitis?

Nasal mucosa pale and boggy

Conjunctiva congested and edematous

Nasla polyps

Cobblestoning

Allergic “shiners”

Allergic “salute”

nasal polyps

Benign tumors found on the nasal turbinates, originating in the maxillary and ethmoid sinuses

what may patients with nasal polyps have in their history?

Nasal obstruction, hyposomia, secondary sinusitis, Samter Triad, Cystic Fibrosis

Samter Triad

nasal polyps, asthma, aspirin sensitivity

pathophysiology of nasal polyps

Recurrent edema of the submucosa associated with rhinitis

diagnosis of nasal polyps

Physical exam: pale/pearly and translucent nodule(s) of inferior turbinates

Nasal endoscopy

Diagnosis of rhinitis

Clinical based on H & P

Testing

Nasal Secretion: + eosinophils on a microscope slide

Rhinolaryngoscopy

CT or MRI

what testing can be done to help diagnosis the cause of rhinitis?

ntradermal testing

Serum IgE, eosinophils

RAST testing

ELISA

whats the treatment for rhinitis?

Avoidance

Intranasal Steroids

2nd Generation H1 antihistamines

1st Generation H1 antihistamines

Alpha-1 receptor agonists

Cromolyn sodium

Leukotriene Inhibitor

Ipratropium nasal spray

Intranasal antihistamine sprays

Opthalmic antihistamine

Surgical removal of polyps

Referral to allergist

Immunotherapy/Hyposensitization

antihistamines MOA

Competitively blocks H1 receptor on glandular tissue

what are possible complications of allergic rhinitis?

Eustachian tube dysfunction

Chronic sinusitis

Sleep disorders/fatigue

Rhinitis medicamentosa

Rhinitis medicamentosa

Tachyphylaxis to intranasal decongestant which causes rebound congestion and turbinate hypertrophy

Urticaria

“Wheals” or “hives” that abruptly appear and flatten within 24 hours per lesion

pathophysiology of urticaria

Vasodilation and increased permeability causes fluid to leak into dermis

Type I hypersensitivity: IgE mediated response to stimulus

H1

increased capillary permeability

H2

arteriolar and venule vasodilation

what are possible IgE immune mediated causes of urticaria?

Contact allergen

Food allergens

Insect venom

Medications

what are possible non-IgE immunologically mediated causes of urticaria?

Bacterial infections

Viral infections

signs/symptoms of urticaria

Pruritus

Erythematous wheals, varying shapes and locations, well-demarcated borders

what are special forms of urticaria?

Angioedema

Papular urticaria

PUPPP

Dermatographism

how do you diagnosis urticaria?

Clinical

History of known exposure

Histologic skin biopsy

Work-up for potential causes

what are treatment options for urticaria?

Treat underlying cause if possible

H1 and H2 antihistamines

Doxepin

Systemic corticosteroids

Omalizumab (Xolair) injections

what are H1 antihistamines used to treat urticaria?

Diphenhydramine, cetirizine, hydroxyzine, fexofenadine

what are H2 antihistamines used to treat urticaria?

Cimetidine, famotidine

anaphylaxis

Acute multi-organ system reaction to mast cell/basophil mediator release

etiology/pathophysiology of anaphylaxis

Exposure to allergen (IgE-mediated reaction) releases histamine

histamine causes what?

Smooth muscle spasm

Vasodilation

Increased vascular permeability

Increased mucous secretion/edema of target tissues

what are signs/symptoms of anaphylaxis?

Low blood pressure

Hives

Itchiness

Flushing

Shortness of breath

Wheezes or stridor

Hoarseness

Pain with swallowing

Cough

how do you diagnosis anaphylaxis?

Clinical

Elevated serum tryptase and histamine

Serum or skin IgE testing

what are treatment options for anaphylaxis?

IM Epinephrine: Antagonizes effect of chemical mediators

Maintain airway I

V fluids: Isotonic

Oxygen

IV Antihistamines

Bronchodilators

Corticosteroids: Prednisone, 1mg/kg/d

Supine position

what can anaphylaxis cause that can lead to mortality?

Respiratory distress/airway collapse/cardiovascular collapse

Type IV Hypersensitivity

Delayed response mediated by T cells

Morbilliform Drug Eruption

95% of all drug eruptions

Erythema Mulitforme

- young adults (20-40)

- 1% of population

Stevens-Johnson Syndrome (SJS)/Toxic Epidermal Necrosis (TEN)

- 2-7 cases per 1 mil people

- more common in immunosuppressed

- females > males

Etiology of Cutaneous Drug Reactions

- medication

- infection

- malignancies

- idiopathic

Medications that can cause cutaneous drug reactions

- anti-seizure medications

- antibiotics

- NSAIDs

- allopurinol

Antibiotics than can cause cutaneous drug reactions

- penicillins

- sulfa

Viral infections that can cause cutaneous drug reactions

- HSV

- AIDS

- Coxsackie

- EBV

Bacterial infections that can cause cutaneous drug reactions

- Group A Strep

- Diptheria

- Mycoplasma

- Mycobacteria

Morbilliform Drug Rash Appearance

- 1-3 weeks after exposure

- generalized multiple patchy/itchy pink/red macules/papules

Important differentiator of morbilliform drug rash

no mucous membrane involvement

Erythema Mulitforme Minor

classic target lesion

Erythema Mulitforme Major

target lesions with mucocutaneous involvement, up to 10% TBSA

TBSA

total body surface area

SJS TBSA

<10%

TEN TBSA

>30%

SJS/TEN Prodrome

- fever

- flu-like sxs 1-21 days

- follow by mucocutaneous lesions

Cutaneous Lesions of SJS/TEN

- coalescing erythematous macules with purpuric centers turn into vesicles and bullae

- tender/burning

- begin on face and thorax and spread in a systemic distribution

Oral Mucosal Lesions of SJS/TEN

stomatitis

Ocular Mucosal Lesions of SJS/TEN

conjunctival/corneal

Diagnosis of SJS/TEN

clinical

Biopsy for SJS/TEN

epidermal necrosis, +CD8

Treatment of SJS/TEN

- stop offending agent

- referral to burn unit

- supportive care

- manage airway

Supportive Care Options for SJS/TEN

- wound care

- fluid replacement

- electrolyte replacement

- pain control

When to use antibiotics for SJS/TEN

prophylaxis - open surface area due to skin peeling away leaves pt open to infections

Prognosis of cutaneous drug reactions

good for everything except TEN

Prognosis of TEN

25% mortality