Dermatopathology: Inflammatory Disorders Flashcards
Syndrome of dermal edema due to mast cell degranulation
Uritcaria
Urticaria involves edema in this skin layer
Dermis
What causes urticaria?
Mast cell degranulation (which causes dermal edema)
What is the typical age of a patient with Urticaria?
Any age, peak age 20-40 years old
Who is more likely to have Urticaria, male or female?
Female > male (2:1 ratio)
Urticaria types involving the immune system exhibit this type of hypersensitivity
Type 1
Are IgE dependent
Type of Urticaria that is commonly acute
IgE dependent types
What triggers the IgE dependent types of Urticaria?
Allergic triggers (e.g. food, insect bites, parasites, drugs)
What type of Urticaria involves mast cell degranulation?
Both IgE dependent and independent types
Type of Urticaria that is typically acute but may become chronic
IgE independent types
Hives –> eventual epidermal hyperplasia, fibrosis, lichenification
Where on the body does Urticaria occur?
In areas of pressure, vibration, or exposure to agent
Dermographism (stroking causes wheal reaction) occurs in these 2 conditions
Urticaria and Cutaneous mastocytosis
What is dermographism?
Stroking causing wheal reaction
As seen in urticaria
When does Urticaria resolve?
Within 30 minutes
Transient rapidly edematous papules/plaques
Superficial dermal edema
Well-defined
Wheals (aka hives)
Edematous papules/plaques in deeper dermis and subcutaneous
Less well defined and lack erythema
Angioedema
Does this describe Wheals or Angioedema:
Superficial dermal edema
Wheals
Does this describe Wheals or Angioedema:
Deeper dermis and subcutaneous
Angioedema
Does this describe Wheals or Angioedema:
Raised erythematous
Wheals
Does this describe Wheals or Angioedema:
Lack erythema
Angioedema
Does this describe Wheals or Angioedema:
Well-defined
Wheals
Does this describe Wheals or Angioedema:
Less well defined
Angioedema
Angioedema without wheals may be caused by this
Hereditary C1 esterase inhibitor deficiency
Hereditary C1 esterase inhibitor deficiency may cause this
Angioedema without wheals
Reaction pattern of epidermal spongiosis
Has many causes
Eczema
Does this describe the acute or chronic phase of eczema:
Pruritic erythematous rash with oozing, edema, vesicles
Acute
Does this describe the acute or chronic phase of eczema:
Acanthosis, hyperkeratosis, lichenification
Chronic
Eczematous rash caused by type I hypersensitivity
Atopic dermatitis
Type of eczema associated with allergic phenotype
Atopic dermatitis
Type of eczema where pathogenesis is uncertain but involves defective water barrier
Atopic dermatitis
What is the typical onset of Atopic dermatitis?
Most begin by age 6 weeks
Most resolve by late childhood, but may persist in adults
Type of eczema often involving face and flexor surfaces
Atopic dermatitis
Type of eczema that is T cell mediated (type IV) hypersensitivity reaction to direct exposure to external antigens
Allergic contact dermatitis
Type of eczema due to chemical or physical exposure to chemicals, often occupations
Not immunologically mediated and much more common
Irritant contact dermatitis
Chronic exposure to irritant or antigen in eczema leads to this
Lichenification
Does this describe the histology of acute or chronic contact dermatitis:
Spongiosis and vesicles
Dermal edema, inflammation with eosinophils
Acute
Does this describe the histology of acute or chronic contact dermatitis:
Epidermal hyperplasia with hyperkeratosis
Mild spongiosis
Chronic
Mild chronic eczema in areas of high sebum production
Seborrheic dermatitis
What is the age peak of Seborrheic dermatitis?
30-50 years
Seborrheic dermatitis is associated with this commensal organism
Malassezia furfur
Malassezia furfur is a commensal organism associated with this condition
Seborrheic dermatitis
High or altered sebum production is associated with Seborrheic dermatitis and occurs during these 2 points in life
Neonatal period
Androgens and puberty
Infantile form of Seborrheic dermatitis is most common in this location on the body
Scalp
Seborrheic dermatitis in infants typically resolves by this age
3 months with decreased sebaceous activity
Acute self-limited CD8+ T cell mediated hypersensitivity reaction to systemic antigen
Erythema Multiforme
What age is the typical patient with Erythema Multiforme?
Any age, most in young adults
Erythema Multiforme is often preceded by systemic infection, especially one of these two
Herpes virus, Mycoplasma
Condition with this morphology:
Interface vacuolar change
Individual keratinocyte apoptosis
Mild spongiosis
Dermal edema and perivascular lymphocytes
Erythema Multiforme
Condition where the classic lesion is a Target lesion
Erythema Multiforme
In Erythema Multiforme, lesions appear within this timeframe
Within 24 hours
Heals in 2 weeks
Acute self-limited CD8 T cell mediated hypersensitivity reaction to systemic antigen that may exhibit Koebner phenomenon (skin lesions that appear in lines of trauma)
Erythema Multiforme
What is the Koebner phenomenon?
When skin lesions appear in lines of trauma (e.g. scratch lines)
Erythema Multiforme with mucosal involvement and fever
Erythema Multiforme Major
Also Stevens-Johnson Syndrome
How is Erythema Multiforme Major different from general Erythema Multiforme?
Erythema Multiforme Major has mucosal involvement and fever
Stevens-Johnson Syndrome is a more severe form of this condition but has mucosal involvement and high fever
<10% of skin surface
Erythema Multiforme
More severe form of Erythema Multiforme with mucosal involvement and high fever, <10% of skin surface
Stevens-Johnson syndrome
More severe form of Erythema Multiforme with diffuse, widespread skin sloughing, full-thickness necrosis (split at DEJ), >30% skin surface
Toxic epidermal necrolysis
More severe forms of Erythema Multiforme (Stevens-Johnson Syndrome and Toxic epidermal necrolysis) are most often due to this
Drug reactions
Prognosis of severe forms of Erythema Multiforme (Stevens-Johnson Syndrome and Toxic epidermal necrolysis) are related to this
Extent of skin loss
Chronic immune mediated disorder of keratinocyte proliferation with environmental triggers
Psoriasis
Psoriasis is associated with these two genotypes
HLA-Cw6 and HLA-B27
HLA-Cw6 and HLA-B27 genotypes are associated with this condition
Psoriasis
What is the typical age of a patient with psoriasis?
All ages, teen and up most common
In psoriasis, T cells release cytokines which cause proliferation of this cell type
Keratinocytes
Infection that will aggravate psoriasis
HIV
Phenomenon seen in Psoriasis when skin lesions appear in lines of trauma
Koebner phenomenon
“Test tubes in a rack” morphology is seen in this condition
Psoriasis (psoriasiform acanthosis)
Auspitz sign (bleeding points when the scales of skin are scraped off) is seen in this condition
Psoriasis
What is the Auspitz sign?
Small bleeding points when the scales of skin are scraped off
Seen in psoriasis
Munro microabscesses (neutrophils in the stratum corneum) are seen in this condition
Psoriasis
In psoriasis, thinned papillary dermal tips lead to this
Auspitz sign (small bleeding points when the scales of skin are scraped off)
In psoriasis, this leads to the Auspitz sign (small bleeding points when the scales of skin are scraped off)
Thinned papillary dermal tips
Thinned papillary dermal tips are seen in this condition
Psoriasis
Where on the body does psoriasis occur?
Sites of trauma: Koebner phenomenon, extensor surfaces (forearm, elbows, low back)
Erythematous plaques with silvery scale are seen in this condition
Psoriasis
Involvement of nails with pitting and ridges may occur in this condition characterized by demarcated scaly, erythematous plaques
Psoriasis
Genotype associated with psoriatic arthritis
HLA-B27
20% of patients with psoriasis also have this, which is associated with the HLA-B27 genotype
Psoriatic arthritis
Plaque forming lichenoid dermatosis
Lichen Planus
What is the peak age of Lichen Planus?
40-50 years
Lesions caused by CD8 T cell mediated reaction against basal keratinocytes with altered self antigen
Associated with environmental exposure
Lichen Planus
What type of T cells are involved in Lichen Planus?
CD8
Dense band of lymphocytes under acanthotic epidermis and “sawtooth” configuration of basal layer are seen in this condition
Lichen Planus
Basal keratinocyte apoptosis seen as “dead reds” is apparent in this condition
Lichen Planus
What are the 5 P’s of Lichen Planus?
Pruritic
Purple
Polygonal
Planar
Papules
Lesions that are pruritic, purple, polygonal, planar, and papules are characteristic of this condition
Lichen Planus
When does Lichen Planus resolve?
Self-resolving, may take 2-3 years
Lesions heal with hyperpigmentation
Fine white lines due to areas of hyperkeratosis that are characteristic of Lichen Planus
Wickham’s striae
Wickham’s striae (fine white lines due to areas of hyperkeratosis) are characteristic of this condition
Lichen Planus
In Lichen Planus, Wickham’s striae is seen as fine white lines due to this
areas of hyperkeratosis
Condition where oral lesions often have lace-like network
Lichen Planus
Androgen dependent plugging of pilosebaceous unit
Acne vulgaris
What is the peak age of Acne vulgaris?
Adolescence
Arises in androgenic stages (Puberty, Cushing Syndrome, PCOS)
Pathogenesis of Acne vulgaris is caused by increased proliferation and cohesion of this type of cell at neck of hair follicle
Keratinocytes
In Acne vulgaris, comedones are formed by the accumulation of these 2 things
Corneocytes and sebum
In Acne vulgaris, corneocytes and sebum accumulate to form this
Comedones
Bacteria that causes Acne vulgaris
Cutibacterium acnes (Propionibacterium)
Persistent facial erythema and inflammatory papulopustules
Rosacea
What is the typical age of a patient with Rosacea?
Middle age
Who is more likely to have Rosacea, male or female?
Equal
Centrofacial erythema, telangiectasias and flushing are seen in this condition
Rosacea
The proposed pathogenesis of Rosacea involves these 2 things
Aberrant immune response and neurovascular dysregulation
In Rosacea, sebaceous hyperplasia may distort tissue architecture, causing this
Phyma
In Rosacea, this may distort tissue architecture and cause Phyma
Sebaceous hyperplasia
Rhinophyma is a common feature of this condition
Rosacea
Prototypical septal panniculitis
Erythema Nodosum
Inflammation of subcutaneous fibroadipose tissue
Panniculitis
Condition that is probably a delayed type hypersensitivity to antigens deposited in subcutaneous tissues
Erythema Nodosum
Condition characterized by sudden onset of red, warm, tender nodules
Mostly on anterior legs
Erythema Nodosum
Where on the body is Erythema Nodosum typically seen?
Mostly anterior legs
When do Erythema Nodosum lesions resolve?
Over the course of a few weeks
Condition involving septa with edema and neutrophils, later with lymphocytes and granulomas with fibrosis
Erythema Nodosum
Epidermal infection with HPV
Warts
Warts are an epidermal infection with this
HPV
Warts are an HPV infection of this skin layer
Epidermis
Common wart, usually of hands
Verruca vulgaris
Common wart located on sole of foot or palm of hand
Verruca plantaris/palmaris
Flat wart, usually of face or back of hand
Verruca plana
Genital wart
Conyloma accuminatum
What is Conyloma accuminatum?
Genital wart
Condition with this histology:
Epidermal hyperplasia
Papillomatosis and parakeratosis
Koilocytes
Prominent keratohyalin granules
Warts
Endophytic growth is painful and seen especially in this type of wart
Verruca plantaris/palmaris
Term for when warts occur as cauliflower like projection above skin surface
Exophytic growth
Common self-limited infection by Pox virus
Molluscum contagiosum
Molluscum contagiosum is a common self-limited infection by this
Pox virus
Condition that forms umbilicated pearly domed papules
Molluscum contagiosum
Invaginated squamous epithelium and keratinocytes that have molluscum bodies are seen in this condition
Molluscum contagiosum
In Molluscum contagiosum, this type of cell has molluscum bodies
Keratinocytes
Fungal infections of keratinized skin
Dermatophytoses
Dermatophytoses of the trunk and extremities
Tinea corporis
Describe the typical patient with Tinea corporis
All ages, especially in hot/humid environments
Dermatophytoses of the scalp
Tinea capitis
Typical age of a patient with Tinea capitis
Usually children
Dermatophytoses that is associated with hair loss (alopecia)
Tinea capitis
Dermatophytoses that is usually seen in children
Tinea capitis
Dermatophytoses that affects all ages, especially in hot/humid environments
Tinea corporis
Dermatophytoses of the beard
Tinea barbae
Dermatophytoses of the feet and hands
Aka athletes foot
Tinea pedis/manus
Dermatophytoses of the genital folds, especially with obesity
Tinea cruris
Tinea cruris is associated with this condition
Obesity
Dermatophytoses that is an infection associated with color changes
Tinea versicolor
Tinea versicolor is caused by infections with this
Malassezia furfur
In Tinea versicolor, Malassezia furfur finfections show “spaghetti and meatballs” in this stain
PAS/GMS stain
Tinea versicolor is most commonly seen on this part of the body
Trunk
Condition with this histology:
Normal appearing skin
May have spongiosis, parakeratosis
PAS stain for fungus in stratum corneum
Dermatophytoses
Superficial epidermal infection
Impetigo
Impetigo is most often caused by either of these two bacteria
Strep pyogenes
Staph aureus
Impetigo is most common in this age group
Children
Impetigo most often affects these parts of the body
Face and hands
Condition that forms pustules that ruptures to form lesions covered by honey colored crust
Impetigo
Toxin mediated production of subcorneal blisters
Staph scalded skin syndrome
What age group is most often affected by Staph scalded skin syndrome?
Infants and children
In Staph scalded skin syndrome, localized Staph infection leads to production of these
Epidermolytic Toxins A and B
In Staph scalded skin syndrome, Epidermolytic toxins A and B binds this
Desmoglein 1
Type of split in Staph scalded skin syndrome
Subcorneal
Staph scalded skin syndrome may remain localized to form this
Bullous impetigo
What is the difference between Staph scalded skin syndrome and Bullous impetigo?
Bullous impetigo is localized while SSSS is the hematogenous dissemination of toxin
Nikolsky sign is positive in these two conditions
Pemphigus Vulgaris and Staph scalded skin syndrome
What is the Nikolsky sign that is seen in Pemphigus vulgaris and Staph scalded skin syndrome?
Blister expands when pressure is applied
Type of split in Toxic epidermal necrolysis
Dermal-epidermal junction
Infection of the superficial dermis with lymphatic involement
Erysipelas
What layer of skin does Erysipelas affect?
Superficial dermis
Erysipelas is most often caused by this
Streptococcus pyogenes
Describe the typical patient with Erysipelas
Affects very young or aged/debilitated
Condition that results in sharply demarcated erythematous plaques and may be associated with fevers
Erysipelas
Erysipelas is an infection of the superficial dermis with this involvement
Lymphatic
Infection of the deeper dermis
Cellulitis
Cellulitis affects this skin layer
Deeper dermis
Cellulitis is most often caused by either of these 2 bacteria
Strep pyogenes and Staph aureus
Condition with localized areas of erythema, deep infection leads to ill-defined borders
Cellulitis
What is the difference between Cellulitis and Erysipelas?
Cellulitis is an infection of the deeper dermis, Erysipelas infects the superficial dermis
Polymicrobial infection of subcutaneous fat/fascia
Necrotizing fasciitis
Necrotizing fasciitis is often initiated by this bacteria
Group A Streptococcus
While Necrotizing fasciitis is often initiated by Group A Streptococcus, this bacteria is also frequently involved
Staphylococcus aureus
Elderly, diabetes, alcoholism, and vascular disease are risk factors for this polymicrobial infection
Necrotizing fasciitis
Condition that may begin as cellulitis but has pain out of proportion to clinical appearance
Necrotizing fasciitis
Necrotizing fasciitis may begin as this, but has pain out of proportion to clinical appearance
Cellulitis