L5 Seborrheic dermatitis, lichen planus, pityriasis, and psoriasis Flashcards
What is seborrheic dermatitis?
- think yellow, greasy looking scale
- occurs in infants, then again as teenagers and adults
- peak prevelance in 3rd and 4th decades
- M>F
- possibly a response to malessezia furfur (yeast) or its metabolites
- > sebaceous glands create a favorable environment for M. furfur which is normally found on skin
What are the characteristics of seborrheic dermatitis?
- COMMON, chronic, relapsing inflammatory dermatitis; can vary from MILD DANDRUFF to more extensive inflammatory dermatitis
- worse with emotional stress and during cold/dry winter months
What is the clinical presentation for infants and adults?
Infants
- CRADLE CAP yellow greasy adherent scales on the vertex of the scalp
- can also be found in diaper area and axillary skin
Adults
- erythematous coalescing macules, patches, or plaques with YELLOW GREASY-LOOKING SCALES
- affects the scalp, face (eyebrows, eyelids, nasolabial folds), ears, pre-sternal skin and upper back
- may be mre extensive and severe in patients with HIV/AIDS and Parkinsons’s disease
What is seborrheic blepharitis?
- periocular presentation
- eyelid edges pink or irritated
- greasy-appearing flakes adherent to lashes
Treatment
-warm compresses and eyelid scrubs are the mainstay of treatment
What is the diagnosis and treatment or seborrheic dermatitis?
-clinical diagnosis based on appearance and location
Treatment
- BLEPHARITIS and CRADLE CAP: olive oil, baby shampoo and warm water to loosen crusts
- SCALP: antifungal agents and topical corticosteroids
- ketoconazole shampoo or cream
- selenium sulfide or anit-dandruff shampoo (selsun, sebulex, head and shoulders) that have anti fungal properties
- FACE: low-potency topical corticosteroid cream, topical antifungal, or combination of the two
What are the characteristics of pityraisis rosea?
- benign, VIRAL SKIN EXANTHEM of unknown etiology
- HHV6/7
- common in TEENS and YOUNG ADULTS; sping and fall
- possible prodrome (H/A, malaise, pharyngitis)
- primary lesion is a HERALD PATCH (usually on the trunk) followed bay a secondary rash 1-2 weeks later
- largely asymptomatic, 50% have mild pruritis
What is the clinical presentation of pityraisis rosea?
- HERALD PATCH- oval slightly raised lesion 2-5 cm, pink or salmon-colored with marginal collarette scale
- Rash- fine scaled, pink, oval papules and plaques
- CHRISTMAS TREE pattern
- “cigarette paper” appearance of some plaques
- SECONDARY SYPHILIS- do serologic test, rapid plasma reagin
What is the treatment for pityraisis rosea?
- reassurance, rash is self-limiting but may persist 6-8 weeks
- oral antihistimines prn pruritis
- loratidine (claritin), cetirizine(zyrtec), diphenhydramine(benadryl)
- medium strength topical corticosteroids
- sun exposure helps
What is the clinical presentation of lichen planus?
- referred to as the “FOUR P’s” pruritic, purple, polygonal, paules or plaques
- papulosquaous eruption characterized by flat-topped violaceous paules
- may affect the skin, genitalia, nails, scalp and oral cavity
- most common places are the wrists, ankles, shins, back, penis, and MOUTH
- Wickham’s striae- tiny white lines running throught the papules
What is lichen planus?
- an immune-mediated response involving activated T cells.
- affects about 1% of population; most frequently ADULTS 30-60y old
- IDIOPATHIC- arises spontaneously
- drugs that can cause it (gold salts, antihypertensives, antimalarials)
- associating with hep C
- KOEBNER phenomenon- development of lesions in sites of trauma (squamous cell also?)
How to diagnose and treat lichen planus?
-skin biopsy can confirm dx : punch or shave biopsy
Treatment
-self-limited disorder (resolves after 1-2 years), tx used to hasten resolution and manage pruritis
*1st line: Topical steroids or intralesional triamcinolone: high potency or super high potency on the trunk and extremities
2nd line: oral steroids, phototherapy, oral retinoids (acitretin) by dermatologist
-other options: cyclosporine (an immunosuppressant)
What is the incidence and etiology of psoriasis?
- M=F women at younger age
- can develop at any age; less common in children than adults
- TWO PEAKS: 20-30 and then 50-60 years of age
- 1/3 of patients have a first-degree relative with psoriasis aka hereditary component
Risk factors and triggers:
-hereditary
-infections (strep throat)
-medications (lithium, beta blockers, antimalarials)
-stress or skin injury (cut or bad sunburn)
-weather (cold/dry)
-tobacco and heavy alcohol use
Triggers can cause psoriasis to appear for the first time or to cause “flare-ups”
what is the pathophysiology of psoriasis?
- overactive T-cells trigger immune response
- increased blood flow/inflammation in the area causes body to make new skin cells more often
- shortened cell cycle for keratinocytes: 36 hours vs 311 hours (normal)
- decreased turn over time of the epidermis: 4 days from basal cell layer to stratum corneum vs. 27 days in normal skin
*skin cells pile up on the surface of the skin=PSORIASIS PLAQUE
What are the characteristics of psoriasis?
- ERYTHMATOUS PLAQUES OFTEN COVERED WITH A SILVERY-WHITE SCALE
- 70% of patients complain of PRURITIS, skin pain or burning
- Various forms: localized or generalized; plaque, pustular, guttate, inverse or erythrodermmic
-can have associated nail psoriasis (nail pits, onycholysis) and psoriatic arthritis (PsA)
What is psoriasis vulgaris clinical presentation?
-most common form affects about 80% of patients
-erythematous plaques with sharply defined margins and thick silvery scale
-esions typically symmetrical
-smaller plaques join together to form larger plaques
Elbows, knees, scalp, umbilicus, intergluteal cleft, gentalia and nails are most commonly afected
*KOEBNER phenomenon and AUSPITZ (little droplets or seeds or blood)
-for auspitz sign: remove the plaque and reveal a smooth, red, glossy membrane with tiny punctate bleeding which are enlarged dermal capillaries
