Augmented Examination

  • Emission of ultraviolet A radiation with peak wavelength of 365 nm
  • Helps diagnose pigmentary disorders and infectious diseases

Examples

  • Green: pseudomonas aeruginosa, microsporum spp. (blue-green to yellow green)
  • White: Vitiligo (chalk-white to blue-white), trichophyton schoenleinii (blue-white)
  • Yellow: Malassezia spp.
  • Orange-red: Propionibacterium acnes
  • Coral red: Corynebacterium minutissimum

  • A hand-held illuminated microscope with a 10-fold magnification
  • Non-invasive technique used to observe morphologic features that are invisible to the naked eye
  • Dermoscopy facilitates diagnosis of pigmented and non-pigmented skin tumors as well as non-pigmented skin conditions e.g. jet with contrail in scabies
  • Can start with the 2-step approach: 1) melanocytic vs non-melanocytic lesion 2) Benign melanocytic vs melanoma

Dermoscopic features of melanoma:

  • Atypical pigment network
  • Atypical vascular network
  • Blue-white veil
  • Multicomponent pattern
  • Non-specific pattern
  • Irregular dots/globules
  • Irregular streaks
  • Irregular blotches
  • Regression structures

Dermoscopic features of lentigo maligna melanoma:

  • Gray pseudonetwork
  • Asymmetric pigmented follicles
  • Annular granular structures
  • Rhomboidal structures
  • Circle in a circle/target (dot in a circle)

Dermoscopic features of acral melanoma:

  • Parallel-ridge pattern

Dermoscopic features of nodular melanoma:

  • Predominant blue-white veil
  • Irregular black globules/areas

Many checklists available to aid on the diagnosis of melanoma via dermoscopy:

  • 3-point checklist:
    • asymmetry, atypical network, blue-white structures
  • 7- point checklist:
    • presence of > 3 features suggest a diagnosis of melanoma
  • Menzies scoring for melanoma: no negative features + 1 of 9 of positive features= melanoma
    • Negative features (2): symmetry of pattern & presence of a single color
    • Positive features (9): multiple colors, broadened network, blue-white veil, multiple blue gray dots, multiple browns dots, peripheral black dots/globules, pseudopods, radial streaming, scar like depigmentation

Vascular structures on dermoscopy:

  • Comma: intradermal and congenital nevi
  • Dotted: melanoma and Spitz nevi
  • Linear- irregular: Melanoma
  • Hairpin: most common in keratinizing tumors, such as seborrheic keratosis and squamous cell carcinoma
  • Glomerular: Bowen disease
  • Arborizing: Basal cell carcinoma
  • Crown vessels: Sebaceous hyperplasia
  • Strawberry pattern: Actinic keratosis
  • Blood crusts over red background: Superficial Basal cell carcinoma