BLASCHKOID DERMATITIS

Introduction

• 1901: German dermatologist Alfred Blaschko (1858-1922) ;retrospective

• No Nervous, Vascular orLymphatic correspondence

• developmental growth pattern of the skin; pattern of EctodermalMigration and Proliferation fromNeural Crest

• V-shape – Upper Back, Neck, Upper Trunk

• S-shape – Lateral Trunk

• Inverted U-shape - breast area / Upper Arms

• Perpendicular - lower extremities, Forearms

• ‘Respect the Midline’

• Koebner's phenomenon but the curvature of the lesions does not support this hypothesis

• Less defined on the head and neck

• Happle et al posterior scalp whereas

• Bolognia et al lateral aspect face and neck

• Equivalent over teeth and eyes

• aa

• aa

Embryological Etiological basis• No Vascular / Nervous / Lymphatic

• Jackson – localization determined by the dermal tissues

• ? Inborn error of morphogenesis due to a single mutant gene

• ? stretching of the skin during embryogenesis

• ? Mosaicism and Lyonization

• aa

Langer's lines / Cleavage lines, -correspond to the natural orientation of Collagen / Muscle fibres. Used in forensic science & surgical techniques.

• Kraissl's lines –anatomical Tension skin lines ; Cadavers• Cox – Tension Skin Lines• Borges – Relaxed TSL

• Voigt Lines – Pigmentary demarcatory lines over body ; the boundaries of theAreas of distribution of the cutaneous nerve stems ;attributed to hormones

• a

• aa

• aa

• aa

• aa

• h

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