Bullous & misc skin Disorders Flashcards
define bullous disorders
Blistering disorders classified based on depth of involvement in the skin
What disease exhibits intraepidermal blisters?
Pemphigus Vulgaris - flacid, break easily
What disease exhibits subepidermal blisters?
Bullous Pemphigoid - tense, do not break easily
What are bullous disorders caused by?
- Infections
- Inflammatory Diseases (BP and PV seen here)
- External Agents
- Metabolic Disorders
- Genetic Deficiencies
What are the ‘miscellaneous’ skin disorders?
- Erythema Multiforme
- Erythema Multiforme Major – SJS
- Toxic Epidermal Necrosis - TEN
- Erythema Nodosum
- Acanthosis Nigricans
Define erythema multiforme
Acute hypersensitivity infl
What is the etiology of erythema multiforme?
- Etiology – 50% idiopathic
- Often associated with preceding infection (HSV, Mycoplasma Pneum., URI) or exposure to drugs, allergens, or physical agents
What is the history asst. with erythema multiforme?
Prodromal Const Symptoms
Short lived – 1mo
+/- Itch, burn, or asympt.
What are the sxs of eryhtema multiforme?
- Early - Eryth macules
- 24-48hrs Later – classic Targetoid/Iris lesions
- Centers become pruritic, cyanotic, +/- vesicular
- Bullae and erosions to oral mucosa may be seen
- Symmetric pattern
- Distributed to dorsal hands/feet and extensor surfaces of arms/legs
How is erythema multiforme treated?
- Mild cases not Tx
- More severe or pruritic cases are Tx with a tapering 3wk course of systemic steroids
- Remove or Tx underlying causes
When is HSV needed in the presence of erythema multiforme?
HSV prevention needed if Herpes associated recurrent EM (not effective if meds given after HSV outbreak)
define steven johnson syndrome
- A Derm Emergency
- A more severe form of EM
- A less severe form of TEN
- Sudden Severe Symmetric vesiculobullous eruption
Who is steven johnson syndrome most commonly seen in?
MC - children and young adults
What is the etiology of SJS?
– 50% drug induced
-bacterial infections, fungal infections, viral infections
What is the prognosis of SJS?
Excellent
Usually self limited w/ 3wk course
Mortality rate 5% if more severe
What are the skin findings in sjs?
- Eryth papules, vesicles, dusky purpuric macules, or EM target lesions seen
- Maximal intensity of lesions 1-2wks
- May be painful or burning
- Mucosal Surfaces x 2
- Distributed mainly to extremities, trunk, face
What drugs can induce SJS?
NSAIDs, PCN, anticonvulsants, doxycycline, tetracycline, minocycline, Sulfonamides
How is SJS treated?
- D/c causative agents
- admit to hospital
- Systemic corticosteroids
define Toxic epidermal necrolysis
A Derm Emergency
More Severe form of SJS
Rare, life threatening exfoliative disease of skin and MM
What is the etiology of TEN?
80% drug induced
What is the prognosis of TEN?
Poor, 25-50% mortality
Occular involvement may scar
What is the % of skin distribution of TEN?
30-100% skin surf, mucosal involvement
How is TEN treated?
- Locate etiology and tx illness or d/c drug
- Tx as severe burn patient
- Supportive care to maintain fluid balance and nutrition, avoidance of infection, control pain and prevention of ARDS
- IVIG therapy being used
Define erythema nodosum
- Is a form of Panniculitis
A. inflammatory infiltration of the Subcutis - Appears as a deep, often nodular, induration or swelling of skin
What is the etiology of erythema nodosum?
- Etiology – considered a delayed hypersensitivity response to variety of antigens
MC Strep infection or Drugs: esp OCP
2.May be idiopathic
How does erythema nodosum present?
Presents as tender eruption of erythematous nodules typically over the pretibial areas.
Typically young female pt
What is the prognosis for erythema nodosum?
- 77% due to infections heal in 7wks
2. 30% of idiopathic cases last >6mo
How is erythema nodosum diagnosed?
- Often made clinically
- If in doubt…
A. Biopsy deep! Need subcutis (punch)
How is erythema nodosum treated?
- Tx underlying etiology
2. Salicylates or NSAIDS
Define acanthosis nigricans
Thickened asymptomatic symmetric velvety hyperpigmented skin to axillae, neck, flexural areas, groin, dorsal fingers
What is acanthosis nigricans asst with?
- Gradual onset – MC seen w/ Obesity and DM
2. Rapid and Ext. onset – rare, malignancy associated ie. stomach adenocarcinoma MC
How is acanthosis nigricans diagnosed?
clinically
What is the treatment for acanthosis nigricans?
- Keratolytics – Lac Hydrin 12%
- Salicytic Acid 6%
- Retinoids
How common is urticaria?
10 – 20% of population experiences Urticaria
Define urticaria
Hives itch secondary to histamine release
Causes = allergens (foods, drugs, pollens)
How is urticaria treated?
Tx of choice are Antihistimines
What are the 4 forms of urticaria?
- Acute = 6wks duration, Labs to r/o metabolic etiol
- Physical Urticaria = pressure, cold, solar, cholinergic
- Angioedema = swelling in the subcutis of skin and mucosa
Define hives
- Hives are transient and last 24hr should be Bx – r/o Urticarial vasculitis
