The Fundamentals of Dermatologic Diagnosis

1. The Fundamentals of Dermatologic Diagnosis Mary E. Hurley, MD Clinical Instructor, UTSW Private Practice, Presbyterian Hospital Dallas

2. What is most difficult of all?It is what appears most simple: to see with your eyes what lies in front of your eyes. Goethe

3. General Observation • Start gathering data the moment you walk in the room • Ask yourself the following questions • Is the patient • awake, alert, and responsive? • well appearing? • acutely ill appearing? • chronically ill appearing? • in distress or uncomfortable?

4. uncomfortable child with atopic dermatitis

5. History and Review of Systems • Make sure you ask appropriate questions in the history and review of systems. • What is the location of the problem? • How long have they had the problem? • Does is itch? • Is it painful? • What makes it better or worse? • What treatments have they tried? • Is the patient on any medicines? • Does the patient have a family history of skin disease or skin cancer?

6. The Skin Exam • Perform a total body skin exam in a systematic and deliberate manner. • This includes the entire skin surface, the hair, the nails, the conjunctiva, and the oral and genital mucosa. • Ideally, the patient would remove undergarments and wear an examination gown only.

7. The Skin Exam Be sure to examine the oral mucosa! Oral erosion in SLE.

8. The Skin Exam • Melanoma can appear anywhere. If you don’t look, you will miss it, and the patient may miss an opportunity for therapy.

9. The Skin Exam • Examination of the skin is an essential part of a thorough patient encounter. • Observation and palpation are the two most important aspects of the skin exam. • Please seek to examine a patient’s entire skin surface. • Patient wearing a gown • Preserve modesty • Good lighting is essential. • Natural light is optimal.

10. The Skin Exam • Specific language used to describe the characteristics of skin lesions • Distribution • Arrangement • Type of lesion • Primary lesion • Secondary lesion • Color • Features based on touch/palpation

11. Distribution • Generalized vs localized • Exposed vs non-exposed • Sun-exposed vs non-sun-exposed • Acral (head, neck and extremities) vs truncal • Extensor (posterior arms, anterior legs) vs flexor (anterior arms, posterior legs) surfaces • Bilateral vs unilateral • Upper vs lower extremity • Dermatomal (following the distribution of a spinal nerve root) • Hair-bearing (non-glabrous) vs non-hair-bearing (glabrous) skin • Follicular vs perifollicular vs non-follicular • Seborrheic (areas with high concentrations of sebaceous glands: e.g. brows, nasolabial folds) • Facial, periocular, perioral • Intertriginous (areas where skin folds on itself) • Mucous membrane • Sites of pressure • Sites of trauma (koebnerization) • Palmo-plantar • Periungual (around the fingernails)

12. Sun Exposed malar rash of acute cutaneous lupus

13. symmetric and generalized

14. dermatomalfollowing the distribution of a spinal nerve root

15. atopic dermatitis involving flexoral areas

16. nickel dermatitis from earring

17. Arrangement • Isolated • Scattered • Grouped • Herpetiform (random grouping) • Zosteriform (grouping in dermatomes) • Circular • Annular (complete ring) • Arciform (incomplete ring) • Polycyclic (multiple rings) • Linear • Angular • Reticulated or mat-like

18. Grouped (herpetiform) herpes simplex infection

19. Grouped (zosteriform) herpes zoster

20. Annular (complete ring) subacute cutaneous lupus pustular psoriasis

21. LinearPsoriasis

22. Type of lesion Primary lesion • Macule - Non-palpable lesion with distinct borders, less than 1 cm in diameter • Patch - Non-palpable lesion with distinct borders, greater than 1 cm in diameter • Papule – Palpable, solid lesion less than 1 cm in diameter • Plaque – Palpable, solid lesion greater than 1 cm in diameter • Nodule – Palpable, lesion more than 1 cm in diameter which is taller than it is wide • Vesicle – Fluid-containing, superficial, thin-walled cavity less than 1 cm • Bulla –Fluid-containing ,superficial, thin-walled cavity greater than 1 cm • Erosion – A skin defect where there has been loss of the epidermis only • Ulcer – A skin defect where there has been loss of the epidermis and dermis • Pustule – Pus containing, superficial, thin-walled cavity • Abscess – Thick-walled cavity containing pus

23. Macule: Non-palpable change in skin color with distinct borders

24. Macule: Non-palpable change in skin color with distinct borders

25. Patch: Non-palpable change in skin color with distinct borders

26. Papule:Palpable, solid lesion less than 1 cm in diameter

27. Papule:Palpable, solid lesion less than 1 cm in diameter

28. Papule:Palpable, solid lesion less than 1 cm in diameter blue nevus

29. Plaque:Palpable, solid lesion greater than 1 cm in diameter

30. Plaque:Palpable, solid lesion greater than 1 cm in diameter psoriasis

31. Plaque:Palpable, solid lesion greater than 1 cm in diameter urticaria

32. Vesicle:Fluid-containing, superficial, thin-walled cavity less than 1 cm

33. Vesicle:Fluid-containing, superficial, thin-walled cavity less than 1 cm

34. Vesicle:Fluid-containing, superficial, thin-walled cavity less than 1 cm varicella with vesicles and bullae

35. Nodule: Palpable, lesion more than 1 cm in diameter which is taller than it is wide

36. Nodule: Palpable, lesion more than 1 cm in diameter which is taller than it is wide neurofibromatosis with multiple papules and nodules

37. Nodule: Palpable, lesion more than 1 cm in diameter which is taller than it is wide

38. Bulla: Fluid-containing ,superficial, thin-walled cavity greater than 1 cm

39. Bulla: Fluid-containing ,superficial, thin-walled cavity greater than 1 cm bullous pemphigoid

40. Erosion: A skin defect where there has been loss of the epidermis only

41. Erosion: A skin defect where there has been loss of the epidermis only toxic epidermal necrolysis

42. Ulcer: A skin defect where there has been loss of the epidermis and dermis

43. Ulcer: A skin defect where there has been loss of the epidermis and dermis pyoderma gangrenosum

44. Pustule: Pus containing, superficial, thin-walled cavity www.medstudents.com

45. Pustule: Pus containing, superficial, thin-walled cavity Inflammatory acne

46. Pustule: Pus containing, superficial, thin-walled cavity pustule over joint in disseminated gonococcemia

47. Abscess:Thick-walled cavity containing pus

48. Abscess:Thick-walled cavity containing pus

49. Secondary Lesions: changes in skin which are superimposed or are the consequence of the primary process • Scale - desquamating layers of stratum corneum. • Crust- dried serum, blood or purulent exudate. Crusts are a sign of pyogenic infection. • Lichenification - skin thickening that is the result of chronic rubbing leading to accentuation of normal skin lines. • Atrophy- epidermal atrophy results from a decrease in the number of epidermal cell layers. Dermal atrophy results from a decrease in the dermal connective tissue. • Scar- a lesion formed as a result of dermal damage. • Excoriation - superficial excavations of the epidermis that result from scratching. • Fissure - a linear painful crack in the skin.

50. Scale:desquamating layers of stratum corneum