Desquamation/Erythemas/Urticaria/Neutrophilic Dermatoses

Question 1

Urticaria/Angioedema

Answer 1

• well-circumscribed area of raised erythema and edema of the superificial dermis
• associated with type I hypersensitivity rxns
• **chronic urticaria > 6 weeks**
• Angioedema = affects of the mucosal tissue of the face, lips, tongue, larynx, hands, feet, and genitalia
• diagnosis: clinical, workup if unknown cause
• tx: avoid food & medication triggers
  
  • antihistamines: cetirizine
  • steroids for severe cases
  • epipen for SEVERE cases
  • omalizubmab for autoimmune etiology = inhibits activation of mast cells

Question 2

Erythema Multiforme

Answer 2

type IV hypersensitivity rxn (delayed) most often caused by HSV and then mycoplasma spp

• target lesions with 3 components: dusky, central area or blister, dark red inflammatory zone surrounded by a pale ring of edema and an erythematous halo on the extreme periphery of the lesion
• NO EPIDERMAL DETACHMENT (Negative Nikolsky sign)
• **most common on extremities and trunk**
• Minor = no mucosal involvement, Major = mucosal involvement
• diagnosis: clinical diagnosis/ biopsy if diagnosis is not clear
• tx: discontinue the drug, antihistamines, analgesics and skin care
• for Oral lesions: corticosteroids + lidocain +diphenhydramine mouthwash
• if severe: systemic corticosteroids

Question 3

Steven Johnson Syndrome /Toxic epidermal Necrolysis

Answer 3

<10% BSA / TEN = >30% BSA

• severe mucocutaneous rxn
• ** medications = most common cause** sulfa drugs, anticonvulsants, and lamotrigine, allopurinol, NSAIDs, antipsychotics, and abx
• Prodromal fever and URI sxs
• widespread flaccid bullae beginning on the trunk and face
• itchy target lesions with purpuric centers
• mucous involvement with NIKOLSKY SIGN

Question 4

Erythema Migrans

Answer 4

associated with Lymes disease

• T-cell mediated response
• bull’s-eye rash associated with myalgias and arthralgias
• diagnosis: clinical diagnosis
• tx: lyme-disease abx: amoxicillin

Question 5

Answer 5

Pyoderma gangrenosum

• associated with Crohn’s dsease
• ulcerative skin lesion secondary to immune dysregulation
• violaceous/ purple/violet irregular, raised or undermined borders with a purulent base
• diagnosis: clinical
• tx: **DO NOT DEBRIDE** inject steroids or systemic steroids
  
  • ​anti-inflammatories: adalimumab or dapsone