Disease secondary to rubbing and/or scratching

Lichen simplex chronics/ Prurigo nodularis/ Picker's nodule/ Erosion/ Ulcer

Fully developed

Epidermal type:

Extensive compact orthokeratosis that resembles the normal stratum granulosum on a palm or sole
Prominent hypergranulosis that resembles the normal stratum granulosum on a palm or sole
Spinous cell hyperplasia
Follicles present in the section

Epidermal and dermal type:

Compact orthokeratosis sometimes with focal parakeratosis; scale-crusts, and erosions if scratching accompanies rubbing
Ostia of infundibula and eccrine ducts often dilated by cornified cells arranged compactly
Hypergranulosis, especially prominent in acrotrichia and acrosyringia
Uneven psoriasiform hyperplasia
Papillary dermis thickened by coarse bundles of collagen in vertical streaks
Dilated capillaries in the thickened papillary dermis in vertical array, i.e., parallel to the bundles of collagen in vertical streaks
Increased number of fibrocytes, some binucleate and others mulinucleate, with abundant stellate cytoplasm in a thickened papillary dermis
Superficial perivascular infiltrate of lymphocytes, occasional plasma cells, and histiocytes, with melanophages among them ranging from sparse to moderately dense; often no infiltrate of inflammatory cell

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