*Develops secondarily to many types of disease (''e.g.'' [[Parasitic skin infections - Pathology|ectoparasites]], [[Mycotic skin infections - Pathology|fungal infections]], [[Endocrine effects on the skin - Pathology|endocrine disease]], internal disease or allergy)
+
*Develops secondarily to many types of disease (''e.g.'' [[Parasitic skin infections - Pathology|ectoparasites]], [[:Category:Integumentary System - Mycotic Infections|fungal infections]], [[Endocrine effects on the skin - Pathology|endocrine disease]], internal disease or allergy)
*Microscopically:
*Microscopically:
**Hyperkeratosis and/or parakeratosis of follicles and epidermis
**Hyperkeratosis and/or parakeratosis of follicles and epidermis