Sparing underneath the concha of the ear in chronic actinic dermatitis – sometimes called Wilkinson's triangle after the late Dr D. S. Wilkinson, one ...
Grouping in a linear distribution ascending the distal limb – so‐called sporotrichoid distribution of a Mycobacterium marinum infection.
Discoid lesions: (a) discoid eczema; (b) discoid hyperpigmentation and unusual haemorrhagic lesions due to the practice of cupping.
Serpiginous lesions on the foot in cutaneous larva migrans.
Pinching and stretching of the skin can elicit diagnostic features in some lesions: (a) pinching a dermatofibroma between the fingers causes it to dip...
A positive prick test to latex.
Sparing of the head and neck by garments in quinine‐induced photo‐lichenoid eruption.
Examples of annular lesions: (a) granuloma annulare; (b) porokeratosis; and (c) tinea corporis.
A collarette scale surrounding an eccrine poroma.
Reticulate lesions: (a) reticulate lichen planus on the lower lip – note also florid lichen planus on the fingers; and (b) erythema ab igne from resti...
Wood's light illumination of erythrasma of the groins – the fluorescence is coral pink.
Characteristic grouping of lesions: (a) blisters in a ring like a ‘string of pearls’ in linear immunoglobulin A (IgA) bullous dermatosis; (b) grouped ...
Examples of arcuate and polycyclic lesions: (a) erythema annulare centrifugum; (b) elastosis perforans serpiginosum – note the abnormal elastic tissue...
Colour and its variability can be diagnostically invaluable: (a) the yellow colour of xanthomas; (b) black, blue, grey and white in a malignant melano...
Digitate lesions in chronic superficial scaly dermatosis.
A reflectance confocal microscope.
Examples of linear lesions: (a) ‘strimmer’ phytophotodermatosis; (b) linear epidermal naevus; (c) growth striae; and (d) lichen striatus.
Livedoid lesions: (a) diffuse dermal angiomatosis of the breast; (b) broken livedo reticularis in cutaneous polyarteritis nodosum.
Target lesions in erythema multiforme.
Blaschkoid lesions in incontinentia pigmenti.
Basal cell carcinoma. A comparison of standard H&E histology and reflectance confocal microscopical appearances.