Dermatology + Infectious Disease

Question 1

Macule

Answer 1

Flat, circumscribed change in skin color (ex: freckle)

Question 2

Papule

Answer 2

Elevated, circumscribed <5mm (ex: mole)

Question 3

Nodule

Answer 3

Elevated, circumscribed >5mm (ex: wart)

Question 4

Vesicle

Answer 4

Small collection of fluid below epidermis <5mm (ex: blister)

Question 5

Bulla

Answer 5

Large collection of fluid below epidermis >5mm (ex: burn blister)

Question 6

Pustule

Answer 6

Visible collection of pus (ex: acne)

Question 7

Wheal

Answer 7

Area of dermal edema (ex: allergic hives), fleeting, irregular shape, itchy, pale at center, red border

Question 8

Placque

Answer 8

Palpable, raised, flat, disc-shaped lesion, solid (ex: psoriasis)

Question 9

Crust

Answer 9

Dried serum + exudate (ex: impetigo)

Question 10

Scales

Answer 10

Accumulation of excessive keratin (ex: dandruff)

Question 11

Ulcer

Answer 11

Circumscribed loss of tissue (ex: pressure ulcer)

Question 12

Cellulitits

Answer 12

Local bact. inf. of dermis + SQ layers as secondary inf. Usually periorbital (s. pneumoniae or Group A str), perivagn./perianal, or in extremity (s. aureus), buccal (Hib).
Previous skin disruption or recent sore throat/ URI, fever/pain/malaise/irrit./anorexia/vomiting/chills, regional lymphad.
Blood cultures if ill appearing kid or <1yr, leukocytosis common
Immedi. atbx thx, hospitalization if acutely ill, febrile <1yr, or periorbital
Complications: septicemia, NF, TSS

Question 13

Impetigo

Answer 13

Common bacterial infection: nonbullous with honey-colored crusts and lesions (70%) or bullous (30%). Cause: group a strept. (S. pyogenes), S. aureus, or MRSA. Nonbullous usually secondary to trauma/primary disease (bites, abrasions, atopic derm., varicella). Bullous is us. sporadic in intact skin in infants/young kids
Bacterial colonization months prior to lesions. More common with poor hygiene or summer, warmth/humidity, lower socioec. groups
Itching common. Weakness/fever/diarrhea with bullous impt.
1-2mm erythematous papules or pustules that progress to vesicles or bullae.
Most common on hands, face, neck, extr., or peineum; regional lymphadenopathy
Topical atbx (mupirocin), oral atbx if widespread or multiple people (augmentin, cephalexin)
Complications: cellulitis, Staph. scaled skin syndrome

Question 14

Patch

Answer 14

Macule, >1cm

Question 15

Secondary skin changes

Answer 15

Atrophy (thinning skin); desquamation (peeling sheets of scale); erosion (oozing, depressed area, loss of epidermis); excoriation (abrasion or removal of epidermis, ex: scratch); fissure (linear, wedge-shape crack); keloid (healed lesion of hypertrophied connective tissue); lichenification (thickening of skin with visible furrows); scales (thin, flaking epidermis layers); scar (healed lesion of connective tissue); striae (stretch marks)

Question 16

Folliculitis

Answer 16

Infected hair follicle; base of the follicle + deep dermis is a boil
S. aureus common, psedomonas may be r/t hot tub folliculitis; E. coli also possible
Pruritus with follic./tenderness with furuncle
Fever/malaise/lymphadenopathy; descrete erythematous 1-2mm papules around hair follicle; face/scalp/extrem/ buttocks/back
Pruritic papules, pustules, or deep nodules where swimsuit covers after hot-tub folliculitis
Management: warm compress, benz. peroxide, topical atbx, oral atbx

Question 17

Vascular skin lesions, descriptive terms

Answer 17

Angioma (papule of blood vessels); ecchymosis (bruise, macular or papular, varied in size); hematoma (collection of blood >1cm); petechiae (pinpoint pink to purple macular lesions that do not blanch 1-3mm); purpura (purple macular lesion >1cm); telangiectasia (collection of macular or raised dilated capillaries)

Question 18

Dermatologic skin lesions, descriptive terms

Answer 18

Acral (extremities); annular (ring-shaped); arcuate (arc-shaped); circinate (circular); confluent (running together); contiguous (touching/adjacent); diffuse/generalized (scattered, wide distrib.); discrete (distinct/separate); eczematous (vesicles with oozing crust); grouped (arranged in sets); guttate (small, droplike); herpetiform (grouped vesicles like herpes); iris (concentric circles); linear (in a line); localized (limited area); nummular (coin-shaped); pedunculated (having a stalk); polycyclic (oval with >1 ring); reticular (netlike); serpiginous (snake-like, creeping); target lesion (iris, erythematous papule or plaque char. by red to violet dusky center surrounded by raised, edematous pale ring and red periphery); umbilicated (depressed in center); verrucous (wartlike); zosteriform (resembling shingles, following nerve root)

Question 19

Topical preparations

Answer 19

Creams (water>oil, used on less dry skin, summertime, high-humidity areas, body folds, apply Q2-3h)
Gels (alcohol based, good penetration, acne and hairy areas)
Lotions (power+water, drying, cooling, soothing actions)
Oils (hold meds to the skin as barriers or occlusive agents)
Ointments (best on dry skin, mostly oil, potent med concentration, occlusive, apply Q12h, greasy feeling, heat retention)
Pastes (powder+oil, difficult to apply/remove, effective)
Powders (absorb moisture, reduce friction, cooling, decrease itching, inc evaporation)
Foam (gas dispersed in lotion containing one+ active substances, effective drug delivery)

Question 20

Medication preparations by potency

Answer 20

1. ointments
2. Creams
3. Lotions
4. Foam

Question 21

Long term local steroid use s.e.

Answer 21

Skin atrophy, striae, increased fragility of skin, hypopigmentation, second. infection, acneiform eruption, folliculitis, miliaria, hypertrichosis (excessive hair growth), telangiectasia, purpura.