Dermatology Quiz: Primary and Secondary Lesions

Module 2: The Skin Exam

• This module focuses on the skin examination for healthcare providers, specifically physician assistants.
• Learning objectives include describing skin lesions using dermatological vocabulary, eliciting a focused dermatological history, describing a focused physical examination, and using bedside diagnostics.

Learning Objectives

• Describe skin lesions using size, shape, color, and distribution.
• Elicit a focused dermatological patient history.
• Describe a focused physical examination of the skin.
• Describe skin scraping/hair shaft with KOH, skin scraping with mineral oil, and Tzanck smear.

History

• Patient History includes HPI, PMH, FH, Surgical Hx, Social Hx, Allergies, and Medications.
• Detailed HPI questions include: Onset (when it started), location, progression, previous episodes, what makes it better/worse, quality (itch, burn, bleed, hurt), treatment, and if the patient has seen another provider.
• Past Medical History should include: Current illnesses, chronic illnesses, history of skin conditions, family history (eczema, psoriasis, skin cancer in the family), and a social history (alcohol/drug use, tobacco use, sexual behavior).
• Allergies and Medications are essential aspects, including atopic triad (asthma, allergic rhinitis, eczema), food allergies, pet allergies, seasonal allergies, and the list of medications the patient is taking.

Patient History: Additional Questions

• Ask if the patient has tried anything to treat the current problem.
• Inquire about exposure to new things (recent camping, hiking).
• Note if the patient is using new products or if there's been recent sun exposure.

Physical Exam

• A systematic approach is crucial for a complete skin exam.
• The exam should include every area of the body, including areas behind and inside the ears, scalp, inside the mouth, axilla, bottoms of the feet, and between the toes.
• Always ask permission before touching.

Palpation

• Assess lesions for roughness, scaling, location (sun exposure), flatness or raised texture, and tenderness.

Fitzpatrick Scale

• A scale used to classify skin types based on their reaction to UV light.

Morphology (Describing Cutaneous Lesions).

• Lesion - abnormal area of skin that differs from surrounding skin.

• Primary Lesions are those arising independently. Examples Include:

  • Macule - flat, non-palpable (<1 cm), color change (freckles, lentigo, flat mole).
  • Patch - flat, non-palpable (>1 cm), color change (vitiligo, cafe au lait spots, port wine stains).
  • Papule - raised, palpable (<1 cm), (pimple, wart, molluscum contagiosum, raised mole, actinic keratosis).
  • Plaque - raised, palpable (>1 cm), (psoriasis, granuloma annulare).
  • Nodule - firm, raised (>1 cm), dome-shaped (epidermal inclusion cysts, lipomas).
  • Vesicle - fluid-filled, blister-like (<1 cm), (herpes simplex, herpes zoster, dermatitis herpetiformis).
  • Bullae - fluid-filled, larger blisters (>1 cm), (bullous pemphigoid, irritant contact dermatitis).

• Purulent Lesions - pus-filled vesicles (foliculitis, paronychia, pimples).

• Wheal - raised, red, pruritic lesions caused by dermal edema (hives, urticaria).

• Secondary Lesions develop from primary lesions, reflecting the evolution or trauma of a primary lesion. Examples Include

  • Excoriation- loss of epidermis & potentially dermis due to scratching
  • Scale - thickening of stratum corneum
  • Fissure - cleft in skin, often painful
  • Lichenification - thickening of skin due to chronic rubbing/scratching (atopic dermatitis, lichen simplex chronicus)
  • Ulcer - loss of epidermis and dermis
  • Crust - dry blood, pus, or serum ("scab")
  • Erosion - loss of epidermis

Color and Size

• Redness includes erythema (localized, blanchable redness), erythroderma (erythema covering at least 80-90% body), telangiectasias (dilation of superficial blood vessels), and violaceous (bruising, non-palpable purpura, actinic purpura, palpable purpura)

Distribution

• Generalized - lesions covering a large body surface area
• Localized - lesions confined to a smaller area
• Flexor surface - lesions on the inner folds
• Extensor surfaces - lesions on the outer sides of body parts
• Intertriginous areas - lesions on folds of skin that rub together
• Palms and soles - lesions on hands and feet
• Acrofacial - lesions on face and extremities
• Photodistribution - lesions appearing in areas exposed to UV rays

Bedside Diagnostics

• Potassium Hydroxide (KOH) - used to detect fungal infections (tinea versicolor, tinea corporis, cruris, pedis, candidiasis). KOH procedure involves preparing a slide with a sample scraped from the lesion and adding KOH to see hyphae under a microscope.
• Mineral Oil - used to diagnose scabies. A scraping is examined under a microscope.
• Tzanck Smear - used to diagnose herpes simplex and zoster infections. The procedure involves scraping the base of the lesion and then staining the sample to observe multinucleated giant cells under a microscope.

Test your knowledge on primary and secondary skin lesions in this dermatology quiz. You will encounter questions regarding various types of lesions, their characteristics, and associated conditions. Ideal for students and professionals in the medical field.