Blistering Disorders Flashcards
Layers of skin
epithelial cell junction
What is the difference between a vesicle(s) and a bulla(e)?
Vesicles are small (<1cm) and bullae are large (>1cm)
types of bullae
A.Vesicles or bullae?
B.Tense or flaccid?
Secondary Changes
Exogenous factors or temporal changes that evolve over time
- •Erosion–Partial loss of the epidermis–Occurs after blisters break
- Ulceration–Full thickness loss of the epidermis–May have loss of the dermis or even subcutis
- Crust–Dried serum, blood or pus on the surface
describe
Erosions in eczema herpeticum
Ulceration in pyoderma grangrenosum
Ulceration in pyoderma grangrenosum
67-year-old M presents with a 4-week history of this intensely pruritic eruption. He has been applying topical Benadryl without improvement. He denies oral involvement.
How would you describe the lesions?
•Multiple tense vesicles and bullae with erosions and crusts in the axilla
Diagnosis?
no oral involvement!
A.Bullous pemphigoid
Bullous Pemphigoid
•Most common autoimmune blistering disorder•IgG antibodies against hemidesmosomes in the epidermal basement membrane leading to subepidermal split•Usually chronic; low mortality•Elderly males•Associated disorders: malignancy, neurological disorders, drugs, autoimmune disorders•Treatment: topical and oral steroids, steroid sparing agents
Bullous Pemphigoid: Clinical Characteristics
•Pruritic, tense bullae arising on an urticarial background•Bullae rupture to leave crusts and erosions•Typically spares oral mucosa
A previously healthy 56-year-old M presents to the Emergency Department with a 4-month history of intermittent painful oral lesions as well as lesions on the face, trunk and extremities. He reports that the oral lesions preceded the skin lesions.
How would you describe the lesions?
•On the neck, back, upper extremities and hard palate, there are widespread erosions
What are your concerns with this much denuded or eroded skin involvement?
•Infection•Dehydration and electrolyte imbalance due to excess fluid loss from skin wounds•Pain•Involvement of the esophagus or other mucosal areas
case 2
Diagnosis?
A.Pemphigus vulgaris
Pemphigus Vulgaris
•Autoimmune blistering disorder•Autoantibodies against desmosomes in the epidermis leads to loss of connection between adjacent cells •May be fatal•M=W•Mean age between 40-60 years•More common in Jewish or Mediterranean descent
Clinical Features: pemphigus vulgaris
- All patients have painful oral erosions •May impair food/liquid intake•Other mucosal sites may be involved
- Skin involvement in 50% of patients•Flaccid bullae and erosions•Intact blisters are rare due to fragility and easy breakage•Painful•Heals without scarring (dermis unaffected), but PIH in darker skin types•Widespread denudation may lead to death from fluid imbalance or secondary infection
Nikolsky Sign
Rubbing the skin causes the epidermis (top layer) to shear away from the dermis (middle layer), leaving a moist surface
positive in pemphigus vulgaris
Treatment Pemphigus vulgaris
•Oral steroids•Steroid sparing agents•Wound care
retuxlmab
Comparison of Bullous Pemphigoid and Pemphigus Vulgaris
Case 3:
A 35-year-old White M presents for a several-year history of an itchy rash on the elbows and knees that worsens after eating bread. Denies nausea, vomiting, abdominal pain, diarrhea.
How would you describe the lesions?
Diagnosis?
•Discrete vesicles and erythema on the knee and elbow
A.Dermatitis herpetiformis
Dermatitis Herpetiformis
•Chronic, autoimmune disorder•More common in White men, rare in African Americans and Asians•Most patients (> 90%) have an associated gluten-sensitive enteropathy, but a minority (20%) have GI symptoms•Pathogenesis: IgA deposition in the papillary dermis•Increased risk of thyroid disease (Hashimoto thyroiditis) and small bowel T-cell lymphoma•Treatment: strict gluten-free diet adherence may lead to complete remission and decrease risk of lymphoma, dapsone
In predisposed individuals, oral intake of gluten induces synthesis of IgA antibodies directed against intestinal tissue transglutaminase. Cross reactivity with epidermal transglutaminase leads to cutaneous disease. The associated autoantigen is an epidermal transglutaminase, transglutaminase 3 (TG3).
For treatment, dapsone is effective for the cutaneous lesions only. Patients will notice a rapid improvement within a few days. However, it does not impact GI disease whereas a gluten free diet does. A gluten free diet may be difficult for patients to follow. It takes several months to a year to be effective, but it can improve both cutaneous and GI disease and decrease the risk of lymphoma.
Dermatitis Herpetiformis: clinical features
- Intermittent papulovesicular eruption•Lesions are often grouped (i.e, herpetiform)
- Symmetric distribution on extensor surfaces of extremities, buttocks, and scalp
- Extremely pruritic •Intense pruritus leads to secondary excoriations, which may be the only cutaneous finding
after eating gluten
case 4: A 32-year-old F PMH cold sores presents for a one-day history of the following eruption on her arms and legs. She also reports painful bumps on her lips, which appeared before the eruption. She does not take any medications. Denies cough or other URI symptoms.
How would you describe the lesions?
What is the diagnosis?
•On the dorsal hand, there are scattered targetoid lesions
A.Erythema multiforme
What is the most common trigger of erythema multiforme in adults?
A.Herpes simplex virus: A preceding HSV infection is the most common precipitating factor; occasionally, there are other preceding infections (e.g., mycoplasma) or, rarely, drug exposure
Erythema Multiforme
Self-limited but potentially recurrent
▪ Abrupt onset of papular “target” lesions, majority of lesions appear within 24 hours
▪ Target lesions favor acrofacial sites
▪ Mucosal involvement and systemic symptoms may be present
Case 5: A 28 year-old F with no significant PMH presents for a painful sunburn on her back after spending the weekend at the beach. She reports that she forgot to reapply sunscreen.
Which of the following is false regarding sunburn?
A.It is an acute inflammatory reaction due to excessive UV light exposure
B.It is a risk factor for development of basal cell carcinoma, squamous cell carcinoma and melanoma
C.It can cause DNA damage, inducing apoptosis of keratinocytes
D.UVB is dominant in sunburn
E.UVA is dominant in photoagingF.It is more common in lighter skinAll of the above are true
All of the above are true
A sunburn is similar to what type of thermal burn?
A.First degree
Thermal Burns
•Clinical presentation depends on depth of injury•First degree: superficial; limited to epidermis•Painful, no bullae, heals without scar•Second degree: partial-thickness•Superficial variant•Epidermis/superficial dermis•Painful, bullae, mild but variable scarring•Deep variant•Epidermis and most of dermis, including follicles•Painful but reduced sensation, bullae, thick scars and wound contractures•Third degree: full-thickness epidermis and dermis•Little to no pain, white, dry, charred, significant scarring
Rule of 9s
•Burn severity is based on depth and body surface involvement (BSA)•BSA is estimated in adults by the “rule of nines”•Cannot be applied to infants and children due to relatively increased head:trunksurface ratio (e.g, head accounts for 19% BSA in 2-year-olds)
A patient presents with painless burns covering the entire left leg (front and back) and the front side of the right arm. What percent body surface area is involved? Given the absence of pain, what type of burn did the patient likely sustain?
A.22.5% BSA, third degree:
Entire left leg = 18%
Front side of right arm = 4.5%
Total = 18+4.5 = 22.5%
Little to no pain in third degree burns
Kodachromes
dermatitis hermetatis
bulbous imtepgo
pemphigus vulgaris
desmosomes
erythema multiforme
