week 4- skin Flashcards
o What is weight and area of the skin? Function?
o Weighs an average of 4 lbs, covers 2 sq m
o Barrier, excretory functions
o What are the layers of the skin, and what’s they incude?
o Epidermis: Basement membrane
o Dermis: Appendages; Blood vessels and nerve endings
o Subcutaneous/Hypodermis layer: Appendages; Fat layer
What may be the cause of a skin lesion?
Infection; Infestations; Sun; Autoimmune; Allergy; Internal disease; Cancer- either skin or internal; Environmental; Iatrogenic; Congenital; Hormonal; Nutritional Deficiency; Emotional
o What questions should you ask for Hx with a skin lesion?
- Where is the lesion/rash located?
- When did it first appear?
- Has it spread or changed locations?
- Is there any sensation associated with it?
- Has the appearance changed?
- Does anything make it worse or better?
- Does anyone else around you have it?
- Recent travel?
- Change in exposures?
- Have you treated it with anything?
What is some additional hx info to gather about a skin lesion?
o History of atopy (atopic dermatitis/eczema)
o Occupational, household and other skin exposures (contact dermatitis)
o Sunlight and/or radiation exposure (benign or malignant skin tumors, lupus, polymorphous light eruption)
o General health, systemic disease (diabetes/Candida/tinea, celiac disease/ dermatitis herpetiformis, hep C/ cryoglobulinemia, IBD/pyoderma gangrenosum, many internal diseases/erythema nodosum)
o All medications including OTC, herbs, etc
o Travel history (Lyme, skin infections)
o What should you get from ROS, FH, SH?
o ROS: Organ involvement; Concomitant symptoms (fever, chest pain, GI)
o FH: Atopy, Autoimmune, Malignancy; Anyone else have it?
o SH: Sexual history (syphilis, gonorrhea, warts, herpes)
o How should you do PE of sken lesion?
o Adequate light o Examine all skin areas, including mucus membranes o Palpate the lesion(s) o Skin scraping o Hair, scalp, nails: Wood’s lamp
o what is the atopic triad?
o Allergies, eczema, asthma
o What is a macule? Papule? Plaque?
- Macule: flat, usu less than 10 mm, variable shape, nonpalpable color change
- Papule: elevated, palpable; less than 10 mm
- Plaque: elevated plateau-like lesion greater than 10 mm; superficial;
What is a nodule? Vesicle? Bullae?
- Nodule: firm papule, palpable, extends into dermis or subQ tissue; Tumors: large nodules more than 10 mm
- Vesicle: fluid-filled blister less than 10 mm
- Bullae: vesicles larger than 10 mm
What is a pustule? Urticaria? Scale?
- Pustule: elevated lesion containing pus
- Urticaria (wheals or hives): transient elevated lesion due to localized edema
- Scale: accumulation of epithelium; dry, whitish
What is crust? Erosion? Excoriation?
- Crust: dried pus, blood or serous exudate on the surface usually due to broken pustules or vesicles
- Erosion: loss of epidermis.
- Excoriation: linear erosion, usu caused by scratching
What is an ulcer? Petechiae? Purpura?
- Ulcer: deeper erosions involving the dermis; bleed and scar
- Petechiae: small non-blanchable punctuate foci of hemorrhage
- Purpura: Larger area or hemorrhage, mb palpable; Large areas are bruises or ecchymosis
What is atrophy? Scar? Telangiectasia?
- Atrophy: paper thin wrinkled and dry-appearing skin
- Scar: fibrous tissue replacement after injury
- Telangiectasia: dilated superficial blood vessels
What is secondary morphology/cobnfiguration of skin lesions? Examples?
- shape of single lesion or cluster of lesions:
- Linear
- Annular – rings with central clearing
- Nummular – circular
- Target – rings with central duskiness
- Serpiginous – fungal and parasitic infections
- Reticulated - lacy pattern
• What may be the texture of a skin lesion?
- Verrucous – irregular surface
- Lichenification: epidermal thickening with accentuation of skin lines due to chronic irritation
- Induration: dermal thickening; skin feels hard and rough
- Umbilicated: with a central indentation
What may be the location and distribution of a skin lesion?
- Single versus multiple lesions
- Presence on particular body parts may be significant
- Random versus patterned distribution
- Symmetric or asymmetric distribution
- Sun-exposed areas versus not
- Crosses midline?
What are the colors of skin lesions, and what they indicate?
- Red (Erythema); increased blood flow to the skin
- Orange: hypercarotenemia
- Yellow: jaundice, heavy metal poisoning, myxedema, uremia
- Green: in fingernails, suggests pseudomonas
- Violet: darkening cutaneous hemorrhage, vasculitis
- Gray/blue skin: cyanosis, metal deposits
- Black: melanocytic lesions, infection, arterial insufficiency
- White: tinea, Pityriasis alba, vitiligo
What are some other clinical signs of skin lesions?
- Dermatographism – urticaria after stroking the skin
- Diascopy: pressure to indicate blanching (hemorrhagic lesions don’t blanch, inflammatory lesions do)
- Darier’s sign – stroking lesions causes intense and sudden erythema and wheal formation
- Nikolsky’s sign – bullae formation and erosion following gentle traction pressure
- Auspitz’ sign – pinpoint bleeding after removal of plaques
- Koebner’s phenomenon – development of lesions within areas of trauma
When are diagnostic tests used in skin lesions? What tests?
- Indicated when diagnosis is not obvious with history and physical alone
- Microscopic examination (biopsy): for suspected malignancies, unknown lesions that persist= Punch or shave
- Cultures: fungal, bacterial, viral
- Patch test for allergies
- KOH test: fungus
- Gram stain
- PCR
- Skin scraping for scabies, fungus
- Immunofluorescence, serology
- Wood’s lamp: UV light for fungi
• What is Pruritis?
o Itching is stimulated by chemical and physical stimulation of cutaneous nerve endings. Stimulus may be external or internal. Several mediators of itching exist: histamine, kallekrein, and various peptidases.
• What may you find on hx for pruritis? What testing may be done?
o History: must include drug and occupational/hobby exposures
o Testing: biopsy, CBC, liver, kidney, thyroid function, evaluation for underlying malignancy, immunoglobulins
• What is cause of pruritis?
o Dry skin most common cause
o Itching may occur with or without an associated skin eruption, which may help determine the cause.
• What is urticaria? 2 types? Etiology?
o Migratory, erythematous pruritic plaques. Mostly involves release of histamine
o Acute vs Chronic: >6 weeks duration?
o Etiology: viral/bacterial infection, IgE allergy, medications esp NSAIDS. Rare- autoimmune dz, malignancy,
• What can you find on hx for urticaria? What PE? What tests?
o History: duration, triggers, frequency, concomitant sxs (GI). Always ask about resp system. Also – use of drugs, travel and family history
o PE: Complete examination of skin, sign of infections or systemic disease.
o Testing: CBC, Immunoglobulins to foods, ANA or thyroid studies may be appropriate. Biopsy if uncertain.
• What are the acne and related disorders?
o Acne vulgaris; rosacea;
• What is acne vulgaris? Causes?
o Obstruction of the pilosebaceous unit presenting with comedones (white/blackheads), papules, pustules, inflamed nodules, superficial pus filled cysts and sometimes deep purulent sacs.
o Causes: androgen stimulus, sebum, bacteria interaction, drug induction, diet (milk, sugar, bromine)
• What is epidemiology of acne vulgaris? Where is it distributed on skin? Ssx?
o Age: Puberty - age ~35.
o Gender: M>F
o Distribution: Face, chest, back, upper arms
o S/Sxs: comedones, papules, pustules, nodules, cysts (actually very rare).
• How is acne vulgaris diagnosed? What labs may be done?
o Dx by H & P: comedones and often several stages of lesions. Grade by severity (mild = 5 cysts or >125 lesions)
o Labs: Serum total/free testosterone w/DHT, FSH, LH, DHEA-S. Bacterial and fungal cultures can be done to r/o infectious folliculitis
• What is ddx of acne vulgaris?
o rosacea (no comedones), perioral dermatitis, drug eruptions, folliculitis (yeast or bacterial, keratosis pilaris, Pseudofolliculitis barbae and acne keloidalis nuchae (in African Americans)
• what is rosacea? Causes?
o chronic inflammatory disorder characterized by facial flushing, telangiectasias, erythema, papules, pustules, and possibly rhinophyma.
o Causes: “Idiopathic” although pts have a higher infection rates of H. Pylori and small intestinal bacterial overgrowth (SIBO)
• What is epidemiology of rosacea? Where is it distributed on skin?
o Ages 30-60, fair complexions, and blushers.
o Distribution: Most on the central area of the face and scalp
What may you find in hx of a pt with rosacea?
o increased susceptibility to recurrent flushing reactions that may be provoked by a variety of stimuli including hot or spicy foods, drinking alcohol, temperature extremes, and emotional reactions.
o may have eye involvement such as foreign body sensation and burning, telangiectasia and irregularity of lid margins, meibomian gland dysfunction (posterior blepharitis), keratitis, conjunctivitis, and episcleritis
what are ssx of rosacea (stages)?
o “Pre-rosacea”
o Vascular phase
o Inflammatory phase-papules, pustules, nodules and cysts present
o Late-stage/rhinophyma
• What are the criteria for diagnosis of rosacea?
o one or more of the following primary features: flushing (transient erythema), Nontransient erythem, Papules and pustules, Telangiectasia and one or more of the following secondary features: Burning or stinging, Plaque, Dry appearance, Edema, Ocular manifestation, Peripheral location, Phymatous changes
• what is ddx for rosacea?
o SLE, discoid lupus, acne vulgaris, drug eruptions, granulomas, perioral derm, infectious folliculitis, seborrheic dermatitis, carcinoid, chronic topical glucocorticoids
• What are the bullous skin disorders?
o Bullous pemphigoid; dermatitis Herpetiformis; pemphigus vulgaris
• What s bullous pemphigoid? Causes?
o Chronic pruritic bullous eruptions. Uncommon
o Autoimmune, drug induced from furosemide, captopril and NSAIDS
• What are ssx of bullous pemphigoid?
o prodromal phase mb with pruritic eczematous, papular, or urticaria-like skin lesions that become tense bullae, negative Nikolsky’s sign, may see urticaria early that turns dusky annular lesions. Bullae form on top of erythematous plaques and rupture in about 1 week leaving an eroded base. Pruritis common.
• Where is bulous pemphigoid found on body? Epidemiology? Associated with?
o Distribution: trunk, lower legs, extremity flexures, and axillary and inguinal folds
o Age >60
o Associated with dementia, Parkinson’s disease, and unipolar or bipolar
• How is bullous pemphigoid diagnosed?
o H & P, skin biopsy (from edge of intact blister) shows subepidermal bulla with infiltrate of eosinophils- direct immunofluorescence (Gold Standard) of skin shows IgG and/or C3 in a linear band in basement membrane, serum antibody titers- Anti-BP180 antibodies. Biopsy must be done to dx
• What is ddx for bullous pemphigoid?
o pemphigus vulgaris, dermatitis herpetiformis, erythema multiforme, drug eruptions
• what is dermatitis Herpetiformis? Causes? Ssx?
o Autoimmune, chronic, recurring, intensely itchy, with symmetrical groups of inflamed vesicles, papules and hives.
o Causes: Autoimmune, celiac dz (asx)-often gluten can cause major sxs
o SSX: Burning, severe stinging and itching, and last for weeks to years.
