Dermatology Flashcards

Question

Patch

Answer 1

Definition Circumscribed change in skin color that is flush with the surrounding skin. Lesion is ≥1.0 cm in diameter Example Café au lait spot Vitiligo

Answer 2

A solid or cystic elevation \<1.0 cm in diameter Example Acne Eruptive xanthoma

Answer 3

A solid or cystic elevation \>1.0 cm but \<2.0 cm in diameter Example Dermato-fibroma

Answer 4

A solid cystic elevation \>2.0 cm in diameter Example Follicular cyst

Answer 5

An elevated lesion that is \>1.0 cm in diameter Example Psoriasis

Answer 6

Desiccated, thin plates of cornified epidermal cells that form flakes on the skin surface Example Ichathyosis

Answer 7

Circumscribed, flat-topped, firm elevation of skin with a well-demarcated and palpable margin Example Uritacaria

Answer 8

Circumscribed, elevated lesion containing clear serous or hemorrhagic fluid that is \<1 cm in diameter Example Contact dermatitis Herpes simplex

Answer 9

Circumscribed, elevated lesion containing clear serous or hemorrhagic fluid that is \>2 cm in diameter Example Bullos pemphigoid

Answer 10

A vesicle containing purulent exudate Example Folliculitis

Answer 11

A depression from the surface of the skin with underlying loss of epidermal or dermal substance Example Lichen sclerosis et atrophicus

Answer 12

A depression from the surface of the skin with a loss of all or part of the epidermis --Burn Can be a secondary lesion --ruptured bulla

Answer 13

A depression from the surface of the skin with a loss of the entire epidermis and at least some of the dermis Example Ecthyma

Answer 14

Dry, leathery thickening of the skin with exaggerated skin markings Example Chronic eczema

Answer 15

An elevated or depressed area of fibrosis of the dermis or subcutaneous tissue resulting from an antecedent destructive process Example healing wound

Answer 16

A deep linear split in the skin extending through the epidermis Example traumatized eczema

Answer 17

Dried exudates of serum, blood, sebum, or purulent material on the surface of the skin Example Acute and/or secondarily infected eczema

Answer 18

Autoimmune, blistering disease (IgG vs. BP180 proteins in hemidesmosomes in the basement membrane zone). Activates complement, get subepidermal blister.

Answer 19

Autoimmune, blistering disease (IgG vs. desmoglein 3 proteins in intercellular desmosome junctions). Results in intraepidermal blister due to loss of keratinocyte cohesion with each other. More serious than BP- the patient can lose a large amount of epidermis.

Answer 20

[EBs in general: blistering diseases due to minor trauma to the skin. "Epidermolysis": lysis of the epidermis. "Bullosa": blistering.] EB simplex is a genetically-mediated disease due to mutations within one of the keratin proteins (K5 or K14) of basal cell keratinocytes. Fragile skin, recurrent blister formation. Blisters formed 'through' the basal cell layer (Wiki says they're formed 'in keratinocytes,' which is about as unhelpful).

Answer 21

"Complex genetic disease influenced by environmental factors." (ie. we have no real idea.) Hyperproliferation and abnormal maturation of keratinocytes, causing thickening of the epidermis. May be some kind of immunologic dysfunction. My skin's on fire!

Answer 22

Epidermal inoculation of latent HPV virus. When activated, the result is local thickening of the epidermis, abnormal maturation of keratinocytes, abnormal stratum corneum. Note we don't actually know why the virus doesn't spread from the focal area of the wart.

Answer 23

Most commonly, basal cell and squamous cell carcinomas. See "Skin Tumors" and "Pigmented Lesions" for more detail. Generally due to UV-induced mutations with a possible contribution from genetic factors.

Answer 24

* Ointments: Water in oil emulsion * Creams: Oil in water emulsion * Gels: Semisolid emulsion in alcohol base * Lotions/Solutions: Powder in water (some oil in water) * Foams: pressurized collections of gaseous bubbles in a matrix of liquid film

Answer 25

Active ingredients delivered in an ointment vehicle have strong potency. Ointments are hydrating, with very low sensitization risk or irritation risk. Body sites most amenable to ointment use are non-intertreginous sites. It’s best to avoid using ointments on face, hands, and groin. Despite of their many therapeutic advantages, some patients dislike greasiness of ointments. Patient education is necessary as ointments may stain clothing.

Answer 26

Active ingredients delivered in a cream vehicle have moderate potency. Creams offer some hydration, but they are not as hydrating as ointments. Creams have a significant sensitization risk and a low irritation risk. Virtually all body sites can be amenable to application of cream-based topical agents. Avoid using cream in sites with maceration (softening and breakdown of skin with prolonged exposure to moisture). There is a high rate of acceptance by patients.

Answer 27

Active ingredients delivered in a gel vehicle have strong potency. Gels are drying. Gels carry a significant sensitization risk and a relatively high irritation risk. Sites most amenable to gel application are oral mucosal surfaces and the scalp. Avoid applying gels on fissures, erosions, or macerated regions. Patient preference for gels is variable.

Answer 28

Active ingredients delivered in a lotion or solution vehicle have relatively low potency. Lotions and solutions tend to be variably drying. Lotions and solutions have a significant sensitization risk and moderate irritation risk. Sites most amenable to lotion or solution application are scalp and intertriginous (where two skin areas touch and may rub together) areas. Avoid using lotion or solution on fissures or erosions. There is a relatively high rate of patient acceptance for lotions and solutions.

Answer 29

Foam vehicles are a relatively newer type of vehicle for topical agents, and I will discuss them relatively more extensively here. The foam matrix is stable at room temperature but readily melts at body temperature. After the foam is applied to the skin, the volatile components (such as alcohol and water) quickly evaporate, leaving behind lipid and polar components containing supersaturated active ingredients to interact with lipids of the stratum corneum. These supersaturated solutions enable maximal delivery of active ingredients into the skin. Interestingly, alcohol, a component of the foam matrix, may play a role in altering the stratum corneum’s barrier properties and lead to improved penetration of the active ingredient. Active ingredients delivered in a foam vehicle have strong potency. Foams are quick-drying, stain-free, and leave almost no residue. Sites most amenable to foam application are hair-bearing areas. Avoid applying gels on fissures or erosions. Patient preference for foam is quite high.

Answer 30

When selecting an appropriate vehicle, three factors are of particular importance: anatomic location, contact allergy/sensitization, and irritancy. As explained in the above text, some vehicles are more appropriate for certain body sites than others. For example, for hair bearing regions, the clinician should consider choosing a solution or foam vehicle over ointment. Various water-based vehicles, such as creams, lotions, and solutions, contain preservatives that may increase the risk of contact allergy and sensitization. These preservatives include known allergens such as parabens and formalin releasers. Irritancy is most notably associated with high concentrations of propylene glycol, other types of alcohols, and certain acidic vehicle ingredients. For example, avoid using formulations containing alcohol or salicylates on extensively fissured, eroded, or macerated areas, which can lead to stinging and burning.

Answer 31

1 FTU is the amount of ointment dispensed from a 5 mm diameter nozzle that is applied to the distal third of the index finger, from the crease under the distal interphalangeal joint to the fingertip. 1 FTU=0.5 g One FTU is enough ointment to cover the front and back sides of one hand. Face and Neck is 2.5 FTU Back is 7 FTU

Answer 32

A large numbers of topical glucocorticosteroid medications are available in a wide range of potency. In general, seven classes have been proposed based on potency. The superpotent topical glucocorticosteroids belong to class 1, and the very low-potency topical glucocorticosteroids belong to class 7. These classes were developed based on vasoconstrictor assays. The following table contains a partial list of these topical steroids. As you will see, the vehicle can greatly influence the percutaneous absorption and efficacy of the some glucocorticosteroids.

Answer 33

``` “The Gentle Touch”: Hydrocortisone 2.5% (cream or ointment) Hydrocortisone 2.5% (cream or ointment) belongs to class 7, the lowest potency class. It is efficacious for mild eczema in children and adults and for treating inflammatory dermatoses involving anatomic regions such as the face, intertriginous areas, or groin, where mid to high-potency topical steroids may be contraindicated. ``` ``` “The Almost All-Purpose Weapon”: Triamcinolone Acetonide 0.1% (cream or ointment): Triamcinolone acetonide is affordable and readily available in many different tube sizes (and even in 1 pound jar!). Triamcinolone 0.1% cream or ointment belongs to class 4, or a mid-potency class of topical steroids. Triamcinolone 0.1% is effective against most moderate spongiotic dermatoses (including eczematous dermatitis, atopic dermatitis, allergic contact dermatitis, arthropod bites, id reactions, drug reactions) involving the trunk and extremities. Long-term use of triamcinolone is not recommended for facial, intertriginous, and groin lesions. ``` “Hercules”: The Clobetasol Propionate 0.05% (cream or ointment) Clobetasol propionate 0.05% cream or ointment belongs to Class 1 of topical steroids, and it is considered one of the most potent topical steroids. Clobetasol is best used in acute eruptions that necessitate relatively rapid amelioration, such as contact dermatitis or acute drug eruptions. Clobetasol should be avoided on the face, intertriginous areas, or the groin, where the skin is relatively thin. Longer-term use of clobetasol requires monitoring of development of adverse effects.

Answer 34

The most common adverse effect is skin atrophy, and this is most commonly associated with long-term use of potent to super-potent topical steroids. Skin atrophy may manifest as shiny, thin skin, telangiectasia, and striae formation. Areas with baseline relatively thin epidermis such as face and intertriginous areas are more susceptible to developing skin atrophy compared to other areas of the body. Extensive and long-term use of potent or super-potent topical steroids have been associated with systemic side effects due to increased systemic absorption of percutaneously delivered active ingredient. Potential systemic side effects include adrenal suppression, Cushing’s syndrome, and growth retardation in children. For example, psoriasis and atopic dermatitis patients may require longer-term use of potent topical steroids to cover larger body surface areas than other dermatologic patient populations. Systemic adverse effects of topical steroids are particularly relevant to these populations. Currently, the AAD guideline for maximum use of class I topical steroids is to not exceed 50 grams per week.

Answer 35

**_Clinical Presentation_**: Appears dry, red scaly and confined to the cheeks (flushed with exposure to cold) and/or generalized eruption characterized by erythematous papules, redness, scaling and areas of lichenification. Must have Itchy skin AND 3 of the following * involvement of skin creases * hx of asthma or hay fever * dry skin * flexural eczema * onset under 2 years of age **_Common Location_**: Flexural surfaces (antecubital fossa, popliteal fossa, neck wrists, ankles). In adults: eyelid, hands **_Association/Etiology_**: Filaggrin gene mutation. Inflammation of the skin. Possible at any age but more common before age 5. **_Miscellaneous Facts_**: associated with asthma and allergic rhinitis Different than Irritant Contact Dermatitis because:

Answer 36

**_Clinical Presentation_**: Non-immunologically mediated reaction (can get reaction from first exposure); caused by the cytotoxic effect of agent, not Th1 and macrophages. Can be severe or mild (mild takes prolonged exposure to cause damage-- like friction). Also presents as pruritic, erythematous papules and plaques. **_Common Location_**: characteristic to exposure. Ex, sweat between skin folds. **_Association/Etiology_**: Common irritants (soap,, skin products, perfume, raw foods, body secretions - sweat/urine, friction). Can develop from single or repeated exposures. **_Miscellaneous Facts:_** none **_Different than Allergic Contact Dermatitis because_**: It is the most common type of contact dermititis, non-immunologic.

Answer 37

**_Clinical Presentation_**: Delayed hypersensitivity immune reaction-- Th1-mediated macrophage activation through inflammatory cytokines IFN-gamma and IL-1. Pruritic, erythematous papules and plaques. Note that first exposure to allergen doesn't usually provoke a response unless it's a week-long exposure or more, but can be 24-48 hours response in repeated exposure. **_Common Location_**: depends on contact. **_Association/Etiology_**: common allergens are repeated/sensitized exposure to small molecules that penetrate through skin to Langerhan's cells where they are taken up by T cells/dendritic cells . * #1: Nickel * Neomycin * Balsam of Peru (sure glad I memorized that one) * Fragrance * Thimerosal * Gold * Quarternium-15 * Formaldehyde * Bacitracin * #10: Cobalt **_Miscellaneous Facts_**: delayed type hypersensitivity reaction (Type IV); diagnosis confirmed with patch testing. Note that certain viruses (like EBV) can kick up a systemic rash similar to drug allergies. Patch testing. **_Different than Irritant Contact Dermatitis because_**: It is not a cytotoxic effect, rather a Type IV delayed hypersensitivity immune reaction.

Answer 38

**_Clinical Presentation_**: Patches, red, scaly and crusty **_Common Location:_** most often occurs on legs but can also present on arms and trunk **_Association/Etiology:_** more common in men \>50yrs **_Tx_**: moisturization, minimize soap and topical corticosteroids **_Different than Atopic Dermatitis because_**: atopic is more common in younger kids and when in older people is on the hands or eyelids, whereas nummular dermatitis is primarily men \>50 affecting their lower legs/arms/trunk

Answer 39

**_Common Location_**: lower extremity edema **_Association/Etiology_**: Seen in association with varicose veins, chronic lower extremity edema, venous stasis ulcers, lipodermatosclerosis **_Complicaitng Factors_**: Dryness, itching, allergic contact dermititis due to topical agents and irritant dermatitis due to wound exudates **_Treatment_**: Compression, elevation, exercise calf muscles, vascular surgery, topical steroids (triamcenelone), avoid allergens

Answer 40

They are diagnosed based on clinical appearance which differs due to the area of inflammation. Dermatitis is typically more superficial in the epidermis. Erysipelas are sharply demarcated plaques primarily in the dermis Cellulitis can be patches or plaques and involve dermis and subcutaneous tissue.

Answer 41

**_Clinical Presentation_**: Flaky, "greasy" **scales**. Facial involvement is usually symmetric over the medial eyebrows, nasolabial folds and ears. **_Common Location_**: areas rich in sebaceous glands (scalp, face, ears, and chest) **_Association/Etiology:_** due to a combination of an over production of skin oil and irritation from a yeast called ***Malassezia furfur*** **_Miscellaneous Facts_**: has also been linked to neruologic conditions including Parkinson's, head injury and stroke. Also linked to HIV **_Different than Psoriasis because_**: "dandruff", commonly involves the scalp, but is more diffuse lesions with finer scale than psoriasis. Cradle Cap * Flaky, white to oily yellowship scale on scalp * Can become confluent with a thick scale covering most of the scalp * Begins one week after birth and may persist for several months

Answer 42

Psoriasis is an immune predisposition + an environmental trigger. Clinical Presentation: **_Common Locatio_**n: Extensor surfaces, may include arthritis (5-20% of patients, also present with joint swelling and nail changes). Can be palmar and plantar. **_Association/Etiology_**: Biopsy is diagnostic - Hyperproliferation of the epidermis with elongation of the rete ridges, neutrophils, and dilated capillary loops in the dermis. Guttate Psoriasis associated with strep throat. **_Miscellaneous Facts:_** May be associated with increased risk of cardiovascular disease due to accelerated atherosclerosis. Psoriasis is systemic inflammation, low grade, favors development of insulin resistance, obesity and metabolic syndrome

Answer 43

**_Cherry angioma_** **Clinical Features**: Red/purple vascular tumor, blanchable, smooth topped papules that typically arise in middle age, typically on trunk, 1-4 mm in size **Diagnose**: most common vascular tumor in adults **Cell type of origin**: vascular **Malignant Potential**?: benign **_Hemangioma_** **_Clinical Features_**: soft tissue tumor of infancy that rapidly proliferates in first 1-3 months of life but over time improve; spontaneous regression 50% by age 5, 70% by age 7 and 90% by age 9. **_Location_**: peri-ocular (obstruct visual field), beard area (can have airway involvement), lip (anorexia), anogenital, nasal tip **_Diagnose_**: Stain with Glut-1 to dx, more common in girls and premature infants and infants of mothers with chorionic villus sampling **_Cell type of origin_**: vascular endothelial cell neoplasm **_Malignant Potential?_**: benign

Answer 44

**_Port wine stain_** ## Footnote **_Clinical Features_**: Congenital (will not regress), irregular **_Diagnose_**: vascular channels that do NOT stain with Glut-1. Somatic mutation in GNAQ. **_Cell type of origin:_** Vascular mutation and depending on how early in development the mutation occurs determines what other abnormalities result. Port wine is mostly a skin disease but 10-15% who had mutations earlier in development may have ocular, neurologic abnormalities including glaucoma, seizures, and developmental delay - Sturge Weber Syndrome **_Malignant Potential_**?: benign

Answer 45

** _Nevus Sebaceus_** Clinical Features: Papillomatous yellow-orange linear plaque on the face or scalp. Lesions on scalp are associated with alopecia. Rapid growth occurs at puberty with enlargement of sebacious glands and epidermal hyperplasia. Diagnose: Somatic mutations in HRAS and KRAS Cell type of origin: Sebacious gland Malignant Potential?: Benign, but 10-30% develop into basal cell carcinomas or syringocystadenoma papilliferum so remove at age 8-12 **_Sebaceous Hyperplasia_** Clinical Features: More common in middle aged and sun exposed. Found on face\>trunk\>extremeties. Generally a primary lesion 1-6 mm yellowish-white papule with central dimple Diagnose: clinical Cell type of origin: sebacioius gland tumor Malignant Potential?: Benign

Answer 46

**_Skin tag/Fibroepithelial Polyps_** ## Footnote Clinical Features: solitary or multiple soft, flesh-colored tan to brown exphytic papule (1-4 mm) with narrow base. More commonly found around intertrigenous areas such as the arm pits, around the neck, groin. Diagnose: clinically Cell type of origin: Essentially fat and connective tissue Malignant Potential?: Benign

Answer 47

**_Lipoma_** ## Footnote **_Clinical Features_**: soft to touch, usually moveable and painless **_Diagnose_**: common in adults age 40-60 but also found in childen **_Cell type of origin_**: adipose **_Malignant Potential?_**: Benign

Answer 48

**_Dermatofibroma_** **Clinical Features**: Mostly found on solitary and on the legs. Primary lesion round to oval firm nodule- depressed or dome-shaped, several mm to 1 cm, rarely larger, skin colored to tan to brown, rarely red or blue, surface may demonstrate scale **Diagnose**: Positive dimple when squeezed = Fitzpatrick sign **Cell type of origin**: fibroblast **Malignant Potential**? benign **_Keloid_** **Clinical Features**: overgrown scar which extends beyond wound borders of either type III or type I collagen. Firm, rubbery, often shiny, pink to dark brown **Diagnose**: clinical, grow beyond wound borders **Cell type of origin**: overgrowth of granulation type III collagen tissue which is slowly replaced by collagen type 1 **Malignant Potential**? benign

Answer 49

**_Seborrheic keratosis_** ## Footnote **Clinical Features**: white to gray to tan to brown to black, exophytic papule "stuck on appearance"/looks like you could peel it off, smooth to verrucous, often friable, surface studded with small pits **Diagnose**: benign tumor of the hair follicle primarily found on head, neck, or trunk (essentially waist up) **Cell type of origin**: keratinocytes **Malignant Potential**? Benign, but the Sign of Leser - Trelat is rapid increase of these (size or number) that is associated with internal malignancies, especially adenocarcinoma of the stomach (60%)

Answer 50

**_Nevi_** ## Footnote **Clinical Features**: infancy to adulthood, any skin surface including mucous membranes, increased in areas of sun exposure **Growth Pattern**: start in dermis (intradermal - papule) then extend to junction between the dermis and epidermis (junctional - macule), then grow outward and extend through epidemis (compound nevis - papule/nodule) **Diagnose**: clinical **Cell type of origin**: melanocytes, congenital nevi melanocytes had migratory errors **Malignant Potential**?: benign, but increased risk for development of melanoma. Dysplastic nevi are contiguous with melanoma 6-70%, controversial.

Answer 51

Criteria: * occurrence of malignant melanoma in 1 or more 1st or 2nd degree relatives * presence of numerous(\>50) melanocytic nevi, some of which are atypical * many of the associated nevi show histological features Pathogenesis * germline mutations * CDK2NA * CDK4 * CMM1 * most people are polygenetic Treatment * mole mapping with dermoscopy * total body photograph * remove most atypical nevi * biopsy atypical nevi

Answer 52

Clinical: * neurofibomas are soft flesh colored papules characterized by the "button hole sign", less commonly appear as deep, firm, subcutaneous nodules, they are focal proliferation of neural tissue within the dermis * Cafe au lait spots are a subtle increase in melanocytes with increased melanin production, congenital or early childhood appearance, trunk and proximal extremities Genetics: Autosomal Dominant but 50% of cases are due to spontaneous mutations in the neurofibromin gene, a tumor suppressor, on chromosome 17 for NF type1 Diagnosis: Requires 2 or more of the following * six or more cafe au lait macules more than 1.5 cm in diameter (0.5 cm in children) * Two or more neurofibromas, or 1 plexiform neurofibroma * Axillary or inguinal freckling (Crowe's Sign) * Optic Glioma * Two or more Lisch Nodules * Distinctive osseus lesion, such as sphenoid wing lesion or thinning of the long bone cortex * First degree relative with the disorder

Answer 53

Basal Cell Carcinoma Incidence: 2.8 million per yr in US, most common malignancy in US Clinical: Pearly shiny papules/nodules that can have talectasias, often sore and difficult to heal if bleed, very superficial on epidermis as they arise from basal cells Genetics: BCC caused by loss of fxn of patch gene which normally blocks smoothened, a transmembrane protein Causes: most common cause is UV radiation (esp. faired skinned people in sunny areas), also occurs after ionizing radiation, arsenic or polycyclic hydrocarbon exposure Malignancy? rare Tx: Vismodegib can help shrink tumors, they can also be surgically removed (Moh's) Subtypes: * Superficial * Nodular (75%) * Micronodular (69% of the 75%) * Pigmented * Infiltrative * Sclerosing/Morpheaform

Answer 54

Squamos Cell Carcinoma Clinical: tend to be hyper-keratotic Epidemiology: 2nd most common skin malignancy, occur more commonly in immune suppressed patients (esp. organ transplant pts.) Risk Factors: * UV damage * thermal injury (burns and burn scars) * radiation * HPV * Chronic Injury Subtypes: * SCC in situ (Bowen's Disease) * Keratoacanthoma (volcano w/ crater) * Invasive SCC Malignancy? Metastasis is rare but in SCC of the lip ranges 10-30%

Answer 55

Epidemiology: most common form of cancer for young adults. Incidence of melanoma in US is increasing 2%/yr. US has a higher rate of melanoma deaths compared to the rest of the world. Clinical: Affects all age groups. Pigmented cancer cells. Mostly superficial or nodular. Location: * Blacks - acral (extremities - distal) and mucosa * Men - back * Women - legs (torso if hx of tanning) Tx: surgical excision

Answer 56

Skin Cancer is the most common form of cancer in the United States \>3.5 million skin cancers in over 2 million people are diagnosed annually Each year there are more new cases of skin cancer than the combined incidence of breast cancer, prostate, lung and colon cancer

Answer 57

Risk Factors: * Transplant patient/immune suppression * CD4 count * medications * heart\>kidney\>liver * (risk increases with # of yrs post-transplant) * Age * Skin type * UV radiation * HPV (65-90% of Squamos cell carcinoma) Specific to malignant melanoma: * Fair skin * excessive sun exposure * immunosuppression * malignant melanoma in a first degree relative * whites * large congenital nevus * sporadic dysplastic nevus syndrome * FAMM (Familial Atypical Moles and Melanoma)

Answer 58

Actinic Keratosis are the most common precancer affecting more than 58 million Americans * 65% of squamos cell carcinomas arise from AK lesions * 36% of basal cell carcinomas arise from AK lesions To reduce risk of developing cancer you can remove AKs by freezing, topical 5 fluorouracil, photodynamic therapy, etc

Answer 59

Patch1 mutation, tx: vismodegib

Answer 60

BRAF mutation, tx: vemurafinib

Answer 61

1. Sun Avoidance (avoid mid-day sun) 2. Sun protective clothing (long-sleeved shirt) 3. Shade 4. Sunscreen (~15 prior to going outside, shot glass, every 2 hours or after swimming/sweating every ~40min) 5. Sombrero (wide-brimmed hat) 6. Sunglasses 7. Self skin examinations 8. See a dermatologist

Answer 62

A=asymmetry B=border irregularity C=color variation D=diameter greater than 6mm E=evolution (or change)

Answer 63

-Damage to DNA, RNA, lipids, proteins * UVB causes: Thymine dimer, pyrimidine-6-4 pyrimidone * UVA causes: Hydroxyguanosine * mostly repaired by Nuclease Excision Repair -Pro-inflammatory effects * cytokines: IL-1, TNFalpha * Mast cells release histamine -Immunosuppressive effects * Langerhan cells move out of the skin induced by TNFalpha, PGE2,GM-CSF * Dangerous b/c can allow non-melanoma cancers opportunity to develop -Induction of innate defenses * WBC are recruited to the skin * Peroxidases, catalases, superoxide dysmutase all protect against reactive oxygen species - Induction of apoptosis * keratinocytes are more susceptible to apoptosis - Vitamin D synthesis * the sun induces the non-enzymatic sythesis and then the active forms are made in the liver

Answer 64

UV (specifically UVB) induces synthesis of Vitamin D3 and D2 in the epidermis. These are then transported to the liver and kidney and activated. Vitamin supplements contain both D2 and D3, mainly D2 (which is less active). There is some controversy over whether the benefits of UV exposure can be fully supplied with vitamin supplementation.

Answer 65

* SPF: sun-protective factor for UVB alone. Should have UVA also. * UVA: involved in photoaging and some melanoma along with UVB * Good sunscreens: UVA has a longer-lasting effect. * Parsol 1789 (avobenzone) = good ingredient (lasting UVA protection) * Neutrogena Helioplex = current gold standard * SPF15 is not sufficient especially for photosensitive, skiers, cancer risk patients, etc- want at least SPF 30. Avoid noontime exposure.

Answer 66

Solar radiation is composed of UVB, UVA, visible light, infrared light, where chronologically the smallest wavelenghts are UVB and the photons with the most energy are UVB. Sun is most intense at noon because the atmosphere has less filtering effects on light, the light has direct line of travel to you at noon whereas earlier or later in the day the light has to travel through more atmoshpere prior to reaching you so it is less intense.

Answer 67

UVC radiation causes corneal burns. UVB radiation causes sunburn. UVA radiation causes photoaging.

Answer 68

- DNA Repair - Apoptosis of Cells with DNA Damage - Defenses Against Reactive Oxygen - Melanin

Answer 69

Melanocytes: produce melanosomes (specialized lysosome) filled with melanin. They transport enzymes and cofactors necessary for melanin synthesis into the cell and prevent leakage of those enzymes and cofactors out (factors to produce melanin are very toxic). Melanocytes develop from neural crest cells and they produce melanin to protect the nuclei of keratinocytes from UV damage. Once melanosome is created (absorbs light across entire UV spectrum), it is transferred to nearby keratinocytes, which carry them as they progress towards the skin surface. Note you make melanin from tyrosine. Mutations from the tyrosine-to-melanin pathway results in albinisms. MITF: key melanocyte-inducing transcription factor: controls melanocytes survival, pigmentation, etc. Can be turned on by Wnt, alpha-MSH, stem cell factor (SCF). May also be activated by UV exposure (more melanin in reaction to more UV). Note that mutations in genes that control expression of the MITF gene can also result in melanoma.

Answer 70

**Skin Cancers** * Melanoma * Basal Cell Cancer * Squamos Cell Cancer **Photodermatoses** * Idiopathic probably immunologic * Solar urticaria (hives), PMLE (rash), actinic prurigo * DNA repair Defects * Xeroderma pigmentosum * Chemical photosensitivity * Drug induced * Porphyria (purpling) * Photoaggrevated dermatoses * Psoriasis * Atopic Dermatitis

Answer 71

enlargment of distal digit tissue, indicative of internal disease enlarged and excessively curved 65% of patients with pulmonary dx will have clubbing Common in congenital heart disease as well Can see in gastrointestinal diesease, malignancy

Answer 72

White nails (leukonychia) except for very distal area cirrrhosis pts

Answer 73

10% of patients in chronic renal failure

Answer 74

seen in immunosupression such as HIV patients

Answer 75

Endothelial malignancy triggered by HHV-8 (human herpes virus 8) Sign of immunosuppresion slowly progressive rusty brownish red tumor Variants * Classic - lower leg of elderly E. european men * Lymphadenopathic - equatorial Africa specific, aggressive * AIDS - associated * 30% of AIDS patients developed this in the 1980s (was a marker for AIDS then)

Answer 76

Skin signs: Exophthalmos (when the eyes are "bug-eyed"), non-pitting edema of lower legs, alopecia, vitiligo

Answer 77

pigment loss, loss of melanocytes can use phototherapy to stimulate melanocytes (narrow band UVB light) melanocytes migrate up from the hair follicles to repigment, areas where there are no hair are more difficult to repigment (fingertips)

Answer 78

Inflammation in the subcutaneous fat CAn palpate easier than noticing surface changes more common in women and on lower legs (shins) associated with fever, malaise and fatigue and infection (strep URI), some medications, sarcoidosis, IBD

Answer 79

Begins in sites of minor trauma (pathergy) Ulcer with necrotic rolled border, starts as pustule with erythematous base more common in patients with IBD (inflammatory bowel disease) Surgical debreadment does not help Can be cleared by cyclosporin

Answer 80

Purple, polygonal, pruritic papules Wickham's striae - lacy white pattern Hepatitis C prevalence is 2-13 X higher always screen for Hep C in these pts. Itchy

Answer 81

Velvety thickening of the skin common in obese and diabetic patients. Stimulation of fibroblasts. Can also occur with malignancy, but when associated with malignancy patients also have weight loss due to adenocarcinoma of the stomach, and usually more rapid onset.

Answer 82

Favors extensor surfaces heliotrope periorbital rash ragged cuticals - samitz sign Gottron's papules over nuckles, knees Shawl sign - rash like a shawl wearing piece of clothing 12% have internal malignancy in adults

Answer 83

mediated by IgE antibodies hives=urticaria Usually begins 7-10 days after you begin taking a medication Usually resolve on their own once you stop taking the drug

Answer 84

Drug interaction due to abnormal drug metabolism and immune hypersensitivity epidermal detachment around mucous membranes \<10% body surface area involvement

Answer 85

drug interaction \>30% surface body involvement like steven-johnsons but more severe sulfur and seizure medications are most common causes

Dermatology Flashcards

(111 cards)