Lecture 1 - The Dermatologic Exam PDF

Lecture 1 – The Dermatology Exam When describing skin findings, there are two major types of lesions: Primary and Secondary. Defining the difference between primary and secondary lesions is somewhat confusing, but in general, the following rule holds: Primary lesions are what initially develop....

Lecture 1 – The Dermatology Exam When describing skin findings, there are two major types of lesions: Primary and Secondary. Defining the difference between primary and secondary lesions is somewhat confusing, but in general, the following rule holds: Primary lesions are what initially develop. Secondary lesions develop as a result of manipulation of the primary lesions, or they develop as part of the natural progression of primary lesions. Primary Lesions: 1. Flat (no palpable component, i.e. if you close your eyes you can’t feel anything) a. < 1 cm – macule (Figure 1.1) b. > 1 cm – patch (Figure 1.2) 2. Raised (epidermal and/or superficial dermal localization, i.e. you can feel it) a. < 1 cm – papule (Figure 1.3) b. > 1 cm – plaque (Figure 1.4) 3. Raised (deep dermal and/or subcutaneous fat localization) a. < 1 cm – nodule (Figure 1.5) b. > 1 cm – tumor (usually still called nodule) (Figure 1.6) 4. Fluid filled (serum, not pus) a. < 1 cm – vesicle (Figure 1.7) b. > 1 cm – bulla (Figure 1.8) 5. Hemorrhagic (violaceous, not blanchable – overall called purpura) a. < 3 mm – petechia (Figure 1.9) b. > 3 mm – ecchymosis/purpura (Figure 1.10) (a bruise is one type of ecchymosis; in other words, all bruises are ecchymoses, but not all ecchymoses are bruises) c. deep – hematoma 6. Miscellaneous Primary a. Transient, well defined erythema and edema – urticaria/hive (Figure 1.11) b. Path of a scabies mite – burrow (Figure 1.12) c. Open comedone – dilated follicle with dark material in center (Figure 1.13) d. Closed comedone – Small, flesh colored papule on face (Figure 1.14) Secondary Lesions: 1. Epidermal accumulations a. Discrete keratinocyte accumulations – scale (Figure 1.15) b. Above with WBCs, RBCs, and serum – crust (Figure 1.16) c. Epidermal thickening with accentuated skin lines – lichenification (Figure 1.17) d. Shedding of sheets of keratinocytes – exfoliation/desquamation (Figure 1.18) 2. Change in skin thickness a. Decreased epidermal, dermal, and/or subcutaneous fat thickness – atrophy (Figure 1.19) b. Abnormally thick scar, extends beyond boundary of injury – keloid (Figure 1.20) c. Abnormally thick scar, stays within boundary of injury – hypertrophic scar (Figure 1.21) d. Linear atrophy with fragmented collagen/elastin fibers – stria (Figure 1.22) 3. Changes in pigmentation a. Increased – hyperpigmented (Figure 1.23) b. Decreased – hypopigmented (Figure 1.24) c. Absent – Depigmented (often difficult to differentiate from hypopigmented) (Figure 1.25) 4. Surface defect or break in skin a. Linear break in skin – fissure (Figure 1.26) b. Wider defect with partial thickness epidermal loss – erosion (Figure 1.27) c. Wider defect with full thickness epidermal loss – ulcer (Figure 1.28) d. Linear, fingernail induced trauma causing the above – excoriation (Figure 1.29) 5. Accumulation of pus a. Superficial (looks white) – pustule (Figure 1.30) b. Deep, painful, warm – abscess (Figure 1.31) 6. Miscellaneous Secondary a. Deep fluid filled lesion – cyst (may need to feel the lesion to differentiate a cyst from a nodule) (Figure 1.32) b. Superficial accumulation of RBCs/Serum/Fibrin – Scab (Figure 1.33) The other important parts of describing dermatologic findings: 1. Location (arms, legs, chest, back, face, etc.) 2. Arrangement (how lesions relate to each other – grouped, scattered, annular, linear, etc.) 3. Size  4. Other descriptive terms – color, texture, firmness Examples of descriptions: On the left temple there is a solitary, firm, 1.5 cm, shiny pink nodule with telangiectasias. Figure 1.34 On the back there are numerous, 1-3 cm red plaques with adherent scale. Figure 1.35 On the ulnar aspect of the right hand and forearm there are several red, 0.5 – 1 cm papules in a linear arrangement. Figure 1.36 Just inferior to right lower lip there is a group of 1 mm vesicles on a red base, with the entire group about 1 cm across. Figure 1.37 On the right knee, there is a red, sharply bordered plaque with silver-white scale. Figure 1.38