Misc skin conditions Flashcards
How common is psoriasis? Do genetics and location play a factor?
- affects 1-9% of the pop: more prevalent the further away from the equator
- equal incidences in M:F
- hereditary: up to 40% of pts have first degree relative with psoriasis or psoriatic arthritis
PP of psoriasis?
- normal cell turnover in epidermis takes about 27 days
- cell turnover in psoriasis is reduced to 4 days
- massive increase in number of cells produced and normal cell keratinization doesn’t take place
- subdermal blood vessel dilation also seen (contributes to eryrthema)
- kertatinocytes have shortened cell cycle time of 1.5 days compared to 13 days
- autoimmune component: T lympchocytes and dendritic cells, mult T cells are present in psoriatic lesions, therapies that suppress T cells are very effective
Psoriasis RFs?
- family hx
- strep infection can trigger guttate psoriasis
- meds: BB, lithium, anti-malaria
- smoking, obesity, and alcohol are assoc
- Vit D deficiency? (greater distance away from equator)
Presentation of psoriasis?
- bimodal age distribution: early 30-39 yrs late 50-69 yrs - can also occur in kids but less common than in adults - may be gradual onset or sudden - pruritis is common - hx of improvement with sun exposure
Assoc conditions of psoriasis?
- psoriatic arthritis
- CV disease, malignancy, DM, metabolic syndrome, HTN, IBD, serious infections
- ocular involvement: swollen lids, conjunctivitis, xerosis, uveitis (think autoimmine)
Types of psoriasis?
- plaque
- inverse
- guttate
- erythrodermic
- pustular
- nails
Characteristics of plaque psoriasis?
- MC
- 75-80% of cases
- slow-forming
- stable
- usually well defined and symmetrical
- typically appears on knees, scalp, elbows, lower back, and can affect nails
diff from eczema - b/c psoriasis on extensor sides, more scales
Plaque psoriasis presentation?
- salmon pink papules and plaques, sharply marginated with marked silvery-white scaling
- scales are losse and easily removed by scratching
- removal of scales results in small blood droplets (Auspitz sign)
- plaque at sites of former skin injury (koebner’s phenomenon)
- plaques turn to powder if manipulated, have odor
Etiologies of koebner’s phenomenon?
- psoriasis plaques that form at site of skin injury
- up to 50% of pts may experience this
- occurs 1-2 wks after injury
may occur from: - bug bites
- bruises and scrapes
- poison ivy or poison oak
- burns, chemical and sunburn
- constant pressure and rubbing, vaccinations, skin blemishes, herpes, chickenpox, acupuncture
Distribution of psoriatic lesions?
- often symmetrical
- favors elbows, knees, scalp and intertriginous areas
- uncommon on the face
- single lesion or lesions localized to one area or can be over the entire body
What is inverse psoriasis?
- sharply demarcated plaques
- found in axilla, groin, naval, submammary region, palms, scalp, and soles
- no scales like plaque psoriasis
- more common in overwt pts
- diff to distinguish from candidiasis w/o bx (look for satellite lesions, KOH)
What is Guttate psoriasis?
- AKA: eruptive psoriasis: has an abrupt onset
- characteristically occurs in young adults and kids: strong assoc b/t recent strep infection (usually pharyngitis) in preceeding 2-3 wks
- mult small teardrop shaped erythematous papules on arms, trunk
- scattered diffusely on proximal extremtities
- usually self limiting in a few weeks to months
What is erythrodremic psoriasis?
- most generalized: often affects most or all of body’s surface
- erythema and scaling from head to toe: skin looks burnt, sheds in sheets
- inflammatory
- least common
- severe itching and pain as skin reddens and sheds
- HIGH RISK of SYSTEMIC INFECTION and electrolyte imbalances
- need inpt management
What is pustular psoriasis?
- can be generalized
- severe form with life threatening complications
- acute onset of widespread erythema, scaling and sheets of superficial pustules with erosions characterizes the most severe variant
- can be assoc with malaise, fever, diarrhea, leukocytosis, and hypocalcemia
- a milder form may just affect the fingers
What are the most common precipitating factors for erythrodermic and pustular psoriasis?
- acute withdrawal of systemic corticosteroids
- can occur in those with other forms of psoriasis but also occurs in pts w/o psoriasis
What is nail psoriasis closely assoc to?
- psoriatic arthritis
- may appear b/f onset of cutaneous psoriasis
- nails have pitted appearance, may lift up (onycholysis - oil drop sign)
Have to distinguish nail psoriasis with subungual hyperkeratosis from what?
- from fungal infection
- do KOH
General tx guidelines for plaque psoriasis?
tx:
exacerbating factors
use both systemic and topical therapy
What are some drugs that may exacerbate psoriasis?
Soln to this?
- BBs, NSAIDs, lithium, ACEI, digoxin
- consider switching med if possible
- combo therapy for tx is the trend to minimize SEs
What are diff types of topical therapies used for plaque psoriasis?
- emollients
- steroids
- Vit D analogues
- topical retinoids
- Calcineurin inhibitors
- coal tar preps
- phototherapy: UVA, UVB
Use of emollients for tx of psoriasis?
- useful in all cases as adjunct
- hydrate stratum corneum
- decrease water evalp.
- soften the scales of the plaques
- some available agents:
Eucerin
Lubriderm
moisturel - lubricating creams are applied 2x daily after bathing, while skin is still damp.
Use of topical steroids as tx for psoriasis? How long should they stay on these? Diff preps?
- 1st line agent!!
- can be cont. as long as pt has thick active lesions (not worried about long term use causing damage to skin b/c of high turnover rate)
- back off on frequency and strength once better under control
- for thick plaques on extensor surfaces - can use potent preps (betamethasone 0.05% or clobetasol propionate 0.05%)
- often used in conjunction with topical vit D analog, topcial retinoid or UVB therapy
Use of vit D analogues? Ex?
Calcipotriol (Dovonex):
- causes immune modulation
- used in mild to mod plaque psoriasis
- SEs include hypercalcemia and hypercalciuria when topical doses exceed 100g/wk
- too irritating for face or groin
- may be used as monotherapy with steroids for breakthrough or just a few days a week
use of Vit A derivatives (retinoids) in psoriasis tx?
Tazarotene (Tazorac):
- modulates differentiation and proliferation of epithelial tissue and exerts some degree of anti-inflammatory and immunological activity
- may cause skin irritation
- effective with little systemic absorption
Use of Calcineurin inhibitors? What areas are these good to use on?
Tacrolimus (Protopic)
Pimecrolimus (Elidel)
- inhibits T-lymphocyte activation by binding to intracellular protein, FKBP-12 and complexes with calcineurin dependent proteins to inhibit calcineurin phosphatase activity
- good to use on intertriginous areas and the face where steroid use should be limited
- not generally used as mono therapy as steroids are most effective
Use of coal tar preps for psoriasis tx? Downside?
- when used alone only as effective as mild-mildpotency topical steroids
- primarily used as add on therapy
- also tends to enhance the effects of UVB therapy
- tar shampoos benefical for scalp lesions in combo with topical steroid solns
- OTC
- use is limited by staining of clothes and odor
Use of phototherapy in Psoriasis?
- has antiproliferative effects by slowing keratinization and anti-inflammatory effects by inducing apoptosis of pathogenic T cells
- UV radiation will accelerate photodamage and risk of skin cancer
- UVB
- PUVA: UVA radiation admin. with psoralen bath or oral dose (photosensitizing drug)
Systemic therapy for psoriasis?
- for severe cases resistant to topical tx
- methotrexate
- acetretin (systemic retinoid): psoriatane
- systemic calcineurin inhibitor: cyclosporine
- biologic agents: infliximab (remicade)
- other immune suppressants: Hydroxyurea, azathiprine
What is urticaria?
- hives
- immune mediated skin eruption of well-circumscribed wheals on an erythematous base
- IgE mediated
What is angioedema?
- hypersensitivity rxn involving the deep layers of skin (fluid influx)
- swelling of the lips, eyelids, palms, soles, genitalia
- 50% urticaria+angioedema
- 40% urticaria alone
- 10% angioedema alone
PP of urticaria and angioedema?
- allergen - leads to IgE ab attached to mast cell - sudden releas of immunologic mediatiors - lead to inflammation
- idiopathic chronic urticaria thought to be caused by autoimmune process
- principle mediator released by mast cell is histamine
Presentation of urticaria?
- characteristic edematous, erythematous, well-circumscribed blanching wheals
- these can range from a few mm to several cm
- serpinginous borders
- lesions may persist for 12-24 hrs but most resolve sooner than this
Presentation of food and drug induced urticaria?
- attacks tend to be brief
- usually don’t cause chronic urticaria
- may be accompanied by angioedema
What is dermatiographism?
- gentle stroking of the skin produces immediate wheal and flare response
What is pressure urticaria?
- pressure to skin at right angle results in red swelling after latent period of up to 4 hrs
What is cold urticaria?
- eruptions w/in minutes following application of cold
What is cholinergic urticaria?
- punctuate hive triggered by exercise or hot shower
What is aquagenic urticaria?
- hives after contact with water
What is solar urticaria?
- hives develop following exposure to UV light
Possible urticaria assocns?
- autoimmune disease: may describe idiopathic cases of chronic urticaria
- infectious disease: sxs tend to occur in prodromal phase of hepatitis B, some pts with chronic idiopathic urticaria had resolution of sxs following tx for H. pylori
Key to eval of urticaria and angioedema?
- thorough hx
- goal is to ID a specific cause or precipitant
- Have pt keep diary
Management of urticaria and angioedema?
- avoidance of etiologic agent if ID
- avoidance of substances that may aggravate:
ASA, NSAIDs, ETOH, ACEI
Use of antihistamines and steroids in sx tx of urticaria and angioedema?
antihistamines:
- sedating and/or nonsedating H1-blockers (benadryl, allegra)
- refractory cases: H2 blockers (ranitidine), 15% of receptors in cutaneous vasculature are H2 receptors
- doxepin (sinequan) is TCA with some H1 and H2 blocking activity
steroids - generally reserved for a trial of max dose of antihistamines
When is subq epi used?
- for severe attacks (anaphylaxis like rxns)
% of pts that are free of urticaric lesions in a yr?
- half of pts with urticaria alone and 25% with urticaria assoc with angioedema are free of lesions w/in 1 yr
What should you look into with a pt that has urticaria and has h&p suggestive of other diseases?
- H. Pylori and thyroid disease
What is Vitiligo? Where do lesions occur?
- onset usually early in life (20-30yo)
- lesions occur primarily on face, upper trunk, finger tips, hands, arm pits, genitalia, bony prominences and perioral region
- hair may be white in involved areas
PP of vitiligo?
- autoimmine mechanism with formation of abs to melanocytes
- often occurs in contrext of other autoimmune conditions such as pernicious anemia and Hashiomoto’s thyroiditis
- not life threatening but can emotionally affect the pt
Tx of vitiligo?
- repigmentation can be achieved to variable degrees with: topical steroids tacrolimus psoralens UVA, UVB surgical skin grafting - long process, reqrs pt commitment - may need pysch support
What is pemphigus? Mortality rate?
- rare, chronic, potentially fatal disease of the mucous membranes and skin
- intraepidermal blistering secondary to an autoimmune process
- mortality rate as high as 5%
Characteristics of pemphigus?
- blistering rash
- flaccid bullae that often begin in oropharynx and then spread to involve scalp, face, chest, axillae, and groin
- bullae are tender and painful
- have nikolsky sign (top skin layer pulls away from bottom layer when rubbed)
- skin bx reqd for dx
Tx of pemphigus?
- recognize and refer
- may reqr hospital admission for severe disease
- tx with systemic corticosteroids and immunosuppressives
What is bullous pemphigoid? May be triggered by? How common is it? MC presentation?
- chronic, subepidermal blistering autoimmune disease
- may possibly be triggered by a drug rxn or infection
- almost exclusively in elderly pop (older than 60)
- 2x as common as pemphigus
- MC presentation is widespread blistering eruption
- increased mortality
Characteristics of bullous pemphigoid? Tx?
- assoc urticarial plaques
- blisters are tense and fluid filled
- skin bx reqd
tx:
- recognize and refer
- 1st line topical high dose (preferred) or oral steroids
- may reqr immunosuppressants
Epidermoid cysts are aka? Characteristics?
AKA: sebaceous cyst, infundibular cyst, epidermal cyst
- MC cutaneous cyst
- derived from epidermis or epithelium
- becomes filled with keratin and lipid rich debris
- rupture is common, may result in painful inflammatory mass
- may become secondarily infected if ruptures b/c communicates with skin
What is a dermatofibroma?
- very common, button like dermal nodule
- lesion may be tender
- benign but can be confused with dangerous lesions
What are lipomas? What is familial lipoma syndrome?
- benign subq tumors
- soft, rounded, and movable against the overlying skin
- composed of fat cells that have the same morphology as normal fat cells
- some individuals have familial lipoma syndrome, an autosomal dominant trait appearing in early adulthood where an individual may have hundreds of lipomas
- plaques with silver scaling are characteristic of?
- psoriasis
Most common type of psoriasis?
- plaque psoriasis
Relationship of urticaria and angioedema?
- you will commonly see urticaria w/o angioedema
- but you rarely see angioedema w/o urticaria
See frightening bullae with positive nikoksky’s sign w/o hx of trauma or burn - what is it most likely? What should you do?
pemphigus
- call derm immediately
subq vs epidermal characteristics?
- if mass is epidermal (usually a cyst), it is going to feel more fixed
- if subq - generally mobile
