Week 3 - Acute Inflammatory Dermatoses Flashcards
What is urticaria and what mediates it?
- Hives, transient raised wheals that persist for 24 hours
- IgE & Histamine mediated
- Pruritic (need to ask patient for this info)
Acute Inflammatory Dermatoses - Where do they prominently effect? 1.Urticaria 2. Erythema Multiforme 3. SJS/TEN 4. Fixed Drug Eruption 5. Panniculitis Erythema Nodosum Erythema Induratum
- Dermis
- Epi/dermis
- Epi/dermis
- Epidermis
- Subcut.
What is angioedema and why is it dangerous?
- It is deep dermal and subcutaneous swelling
- Burning & painful
- Dangerous: Laryngeal Involvement - swelling of tounge, larynx after swelling of mouth and/or eyes
- Epi is used for these reactions
- Lips, eyes, groin, soles/palms are most common
What is acute urticaria?
It occurs in 2/3 of people and lasts less than 6 weeks. Its usually type I IgE mediated and resolves within hours-days
What are different types of Uritcaria?
- Type I IgE mediated (food, latex, stings, medications, aeroallergins)
- Autoimmune
- Infectious - viral - HIV, hep C
- Physical (solar, cholinergic, cold, dermographism-scratching skin, aquagenic, pressure)
- Direct mast cell degranulation (medications)
- Foods high in histamine
Urticaria Management: What medications are our first and second choices? What do we use for Type I IgE mediated reactions?
First choice: 2nd generation, non-sedating H1-blockers
-Cetrizine (Zyrtec)
-Fexofenadine (Allegra-D)
-Desloratadine (Clarinex)
-Loratidine (Claritin)
Second choice: If symptoms not controlled, add second generation, sedating H1 blockers
-Hydroxyzine (Atarax) at night
-Diphenhydramine (Benadryl) at night
Cyproheptadne (Periactin) -Cholinergic and cold urticarial
-EpiPen!
What is erythema multiforme?
- Usually associated with prescription medications
- Circular lesions on palms, soles of feet, multiple confluent lesions (coming together), raised, erythematous, bilateral (both hands)
- Classic ‘target’ lesions with multiple spots, inflammatory middle-soft, uneven boarder
- Usually occurs in people under 20
What typically causes erythema multiforme?
Drugs - sulfonamides, penicillin, barbiturates, etc.
Infection - herpes simplex virus, mycoplasma
Many cases are idopathic
How to treat EM?
Prevent, Supportive therapy, use medication to control herpes simplex, Glucocorticoids like prednisone to treat severe cases
What is the difference between SJS and TEN?
SJS - <10% dermal attachment
TEM - 30% dermal attachment
They overlap in the 10-30% range
What is SJS?
- Drug induced or idiopathic
- Skin tenderness and erythema (skin & mucosa)
- Cutaneous & Mucosa Epiderma Necrosis & Sloughing
- Potentially life threatening
- +2 mucosal membranes effected and <10% epidermal detachment
What is the proposed mech. for SJS and TEN?
Cytotoxic immune reaction aimed at destruction of keratinocytes expressing foreign (drug-related) antigens
What is toxic epidermal necrolysis? (TEN)
- Maximal variant of SJS with 30% epidermal detachment
- Severe hypersensitivity syndrome - life threatening
- Total detatchment of epidermis (like total body second degree burn)
What are fixed drug eruptions?
- Epidermal
- Usually face & genitals
- Unknown mech
- Can reoccur in same place
- Localized, sharply demarcated erythematous patch that can itch, burn or be asymptomatic
- Caused by a drug
What are the two types of Panniculitis?
- Erythema Nodosum
2. Erythema Induratum
