Inflammatory skin disease Flashcards
Type of dermatitis often seen in association with other signs of venous insufficiency of the lower extremities
stasis dermatitis
complicating factors of stasis dermatitis (3)
dryness
itching
contact dermatitis (allergic due to use of topical preparations (i.e. topical antibiotics) (irritant due to wound exudates)
In what ways can contact dermatitis complicate stasis dermatitis?
allergic due to use of topical preps (i.e. antibiotics)
irritant due to wound exudate
Psoriasis may be associated with increased risk of?
cardiovascular disease
what type of immune response is allergic contact dermatitis -?
delayed type hypersensitivity - (type iv) -
how do we confirm allergic contact dermatitis
patch testing
which type of dermatitis is associated with asthma and allergic rhinitis
atopic dermatitis
etiology of allergic contact dermatitis
common allergens
etiology of irritant dermatitis
common irritants
common etiology of atopic dermatitis
filaggrin
common etiology of seborrheic dermatitis
malassezia furfur (a fungus)
common etiology of stasis dermatitis
lower extremity edema
common location of psoriasis
extensor surfaces
may include arthritis
common location of atopic dermatitis
flexor surfaces
common locations of seborrheic dermatitis
scalp
common location of stasis dermatitis
lower legs
venous stasis ulcers are frequently found in conjunction with?
stasis dermatitis
where are venous stasis ulcers primarily found?
found on the medial lower leg just above the ankle
what color are venous stasis ulcers?
borders?
red in color with yellow fibrinous base
borders are irregularly shaped
may be purulent if infected
treatment of stasis dermatitis?
CAVETE Compression Avoid allergens Vascular surgery Elevation Topical Steroids Exercise calf muscles
Morphology of Dermatitis vs Morphology of Cellulitis
Dermatitis = erythematous papules and thin plaques with scale
Cellulitis = warm, tender, erythematous patches or plaques
Locations of Dermatitis vs. Locations of Cellulitis
Dermatitis = epidermis / dermis Cellulitis = dermis and sub-cu
So, if we see a patient with erythematous papules and thin plaques with scale affecting the dermis and epidermis what would list as our most likely dx?
Dermatitis
So, if we see a patient with warm and tender erythematous patches or plaques affecting their dermis and sub-cu, what would be our most likely dx?
Cellulitis
Jane has a bilateral lower extremity edema and itchy rash. What is her most likely diagnosis
stasis dermatitis
When we talk about dermatitis, what type of dermatitis are we usually talking about?
Spongiotic dermatitis = nonspecific reaction pattern seen on skin biopsy
Will we be able to tell the type of dermatitis based on skin biopsy?
no, will need to know history
Whenever you see a rash on the leg and vericose veins, think?
stasis dermatitis
stasis ulcers generally develop where?
on the medial lower leg
the symmetric distribution with pitting edema noted from socks is classic in patients with?
stasis dermatitis
Pat has a chronic bilateral lower extremity rash with worsening erythema, swelling, warmth, and tenderness in the left leg over the past week. What is the most likely diagnosis?
cellulits
Unilateral rubor, calor, tumor, and dolor extending proximally up the leg is consistent with?
cellulitis
why don’t you get epidermal changes in cellulitis
because it is affecting the dermis - not the epidermis
What is atopic dermatitis and when does it usually begin?
Common skin disease, which may begin at any age, however a majority begin before 5
If we see bilateral symptoms are we thinking stasis dermatitis or cellulitis
bilateral is usually dermatitis… bilateral is uncommon in cellulitis
Atopic diathesis frequently associated with atopic dermatitis? (2)
asthma
allergic rhinitis
atopic dermatitis
Atopic dermatitis is usually considered a disease of?
childhood exzema
Where is atopic dermatitis usually localzied to?
flexures (i.e. anti-cubital fossa)
infantile (0-2) atopic dermatitis usually presents as?
dry, red scaly areas confined to the cheeks
becomes flushed with exposure to cold
atopic dermatitis (>2) characteristic involvement?
flexural skin
- atecubital fossa
- popliteal fossa
- neck
- wrist
- ankles
To diagnose atopic dermatitis, your patient must have X + 3
Must have: Itchy skin + 3
- Onset under 2
- Hx of involvement of skin creases
- Personal hx of asthma or hay fever
- Hx of dry skin within last yr
- Visible flexural eczema
Frequent sites of atopic dermatitis in adults?
eyelid
hand (palm)
*in addition to flexural
Associated features of atopic dermatitis
dry skin (xerosis)
keratosis pilaris
ichtyosis vulgaris
hyperlinearity of the palms
The itch that rashes =
atopic dermatitis
70% of patients with atopic dermatitis have a mutation in?
filaggrin
Ichthyosis vulgaris is a defect in
filaggrin
What skin condition is the number one global burden of disease?
eczema
Is the global burden of eczema increasing or decreasing?
increasing
What would we call a non-immunologically mediated reaction resulting from a direct cytotoxic effect?
irritant contact dermatitis
are irritant contact dermatitis from repeated or single exposures?
could be from either…since it is non-immunologically mediated
how do we test for irritant dermatitis?
there is no specific test for irritant dermatitis
what is the most common type of contact dermatitis?
irritant contact dermatitis
strong vs weak irritants
strong can damage skin even in small amounts - weak are harmless by themselves but repeated contact may damage
examples of weak irritants?
soap skin products perfumes wool raw food (meat, fruit, veggies) body secretions (feces, urine, saliva, sweat) friction
What is intertrigo?
Intertrigo (intertriginous dermatitis) is an inflammatory condition of skin folds, induced or aggravated by heat, moisture, maceration, friction, and lack of air circulation.
What does allergic contact dermatitis require?
Requires contact exposure of an allergen, immune response, and development of “memory” T cells
What type of immune response is allergic contact dermatitis?
Type Iv
When does reaction usually manifest in allergic contact dermatits?
Type IV, delayed type hypersensitivity reaction usually starts 24-48 hours after exposure to the allergen, but it can be delayed longer
What is a contact allergy?
Delayed type hypersensitivity reaction
Poison ivy would be an example of?
Delayed type hypersensitivity
ACD what are allergens usually?
small chemical molecules (haptens) usually
ACD… the small size of allergens (haptens) enables?
penetration through the skin
ACD… how are allergens presented to the immune system?
Langerhans cells present allergen to T cells
ACD…exposures to develop sensitization?
most haptens are weak allergens and require repeat exposures prior to sensitization
ACD…what actually causes the inflammation?
elicitation of ACD caused by inflammatory cytokines including TNF-alpha and IL-1
What is the gold standard test for diagnosing ACD?
Patch testing
Top 3 contact allergens?
Nickel
Balsam of Peru (fragrance)
Neomycin
Risk factors for Nickel sensitivity? (3)
Female
Young (
Is nickel contact dermatitis increasing or decreasing?
increasing
Europe and Nickel?
EU put up regulations on the amt of nickel in products –> the rate of nickel contact dermatitis declined
Fragrance and contact allergens - unscented products?
May still have masking fragrance and cause dermatitis
EU and US fragrance
EU requires labeling of fragrance allergens of certain concentrations
US FDA bans 10
Common topicals that cause allergen dermatitis?
Bacitracin and Neomycin - often occur together
can see co-sensitization
wide-spread use has lead to increase in sensitization
What is the most common type of drug reaction in skin?
Drug eruptions - eczematous eruptions
What is the usual kind of drug eruption?
Cell-mediated type IV hypersensitivity
Are drug eruptions usually localized?
no, generalized
Drug eruption time course
7-14 day after starting a new medication
When would a drug eruption start sooner than 7-14 days?
in cases of receiving an “old” medication (i.e. inadvertent re-challenge)
what is an exanthem?
is a widespread rash usually occurring in children but can occur in adults. An exanthem can be caused by toxins, drugs, or microorganisms, or can result from autoimmune disease.
Exanthematous eruption
what percent in children are drug induced
what percent in adults are drugs induced?
10-20% in children (exanthem in children is more likely to be virus because they are ooey… medical term :))
50-70% in adults
Drugs responsible for exanthematous eruptions?
aminopenicillins sulfonamides cephalosporins anticonvulsants allopruinol
Exanthematous drug eruption…
treatment?
resolution?
treatment
- discontinue offending medication
- supportive care with topical steroids
resolution
- usually 1-2 weeks after stopping drug but can take up to 3 months
What is urticaria?
hives / wheals
We see urticaria in what kind of hypersensitivity?
Immediate type I
mediated by IgE
How long does each lesion in urticaria last?
less than 24 hours
What layer of skin is affected in urticaria?
dermis… so we won’t see scale / blisters
In type I drug sensitivity - what does first exposure generate?
IgE antibodies
In type I drug hypersensitivity - what does re-exposure do?
antigen binds to IgE on mast cells and basophils causing degranulation with release of mediators such as histamine
How do we treat urticaria?
antihistamines
acute urticaria? how long present?
urticaria present less than 6 weeks - 2/3 new onset urticaria will resolve within this time frame
chronic urticaria? how long last?
present for most days, for a period greater than 6 weeks
Top 3 causes of chronic urticaria?
72% idiopathic / autoimmune
20% physical urticaria
2% tie food/vasculitis
chronic urticaria is or is not usually due to food/med
not
What are some examples of physical urticarias?
dermagraphism (stroke) delayed pressure vibratory exercise induced cold solar aquagenic
What is nummular dermatitis
due to dry skin / excess use of soap
also called discoid eczema
Where is nummular dermatitis most common?
legs, but can also be on arms and trunk
who most susceptible to nummular dermatitis?
men>50
nummular dermatitis appearance?
patches which may be red and scaly (discoid) and may become crusty - tends to be stubborn
stop soap use corticosteroids
what is dandruff of the scalp called?
seborrheic dermatitis
what do we call seborrheic dermatitis in bambinos?
cradle cap
what does seborrheic dermatitis look like?
(flaky whit to yellowish oily scale scalp)
can become confluent with thick scale covering most of scalp
when does seborrheic dermatitis start?
begins 1 week after birth and may persist for several months (cradle cap version)
Seborrheic dermatitis in adults
- facial involvement?
usually symmetric facial involvement over the medial eyebrows and nasolabial folds
- occurs in areas rich in sebaceous glands (scalp/face/ears/chest)
What characterizes seborrheic dermatitis?
flaky / greasy scales
What is seborrheic dermatitis though to be due to?
a combination of an over production of skin oil and irritation from a yeast called MALASSEZIA FURFUR
What has seborrheic dermatitis been linked to?
Neurologic conditions - including parkinsons / head injury / stroke
HIV
How would you distinguish psoriasis dandruff from seborrheic dermatitis dandruff?
seb derm is more diffuse with lesion of finer scale
what percent of population has psoriasis?
2
what percent of patients with psoriasis have +FH?
36
Histology of psoriasis?
hyperproliferation of the epidermis with elongation of the rete ridges, neutrophils and dilated capillary loops in the dermal papillae
4 subtypes of psoriasis?
chronic plaque disease
guttate
erythroderma
pustular psoriasis
guttate psoriasis is associated with?
strep
what percent of patients with psoriasis get psoriatic arthritis?
5-20
comorbidities of psoriasis?
persistent low grade inflammation favors the development of insulin resistance, obesity, and metabolic syndrome
psoriasis is an independent risk factor for?
cv disease
patients in their 40s with psoriasis
increased risk for MI?
Severe 2x
mild 1.2x
psoriasis localized disease treatment?
Calcipotriol (VitD3) corticosteroids topical retinoids phototherapy - UVB. PUVA
psoriasis widespread disease treatment?
methotrexate cyclosporin systemic retinoids biologics - anti T-lymphocyte - anti TNF alpha
Seborrheic dermatitis is usually a result of sensitivty to ?
Yeast (MALASSEZIA FURFUR)
Psoriasis vs Seborrheic dermatitis
size of scale
psoriasis tends to occur on which surfaces?
extensor
psoriasis WBC character?
neutrophils
Psoriasis onset usually 2 things?
genetic predisposition with environmental trigger
psoriasis is independent risk factor for metabolic syndrome due to …
systemic inflammation
