Types of porokeratosis

Classic porokeratosis of Mibelli (PM)
Disseminated superficial actinic porokeratosis (DSAP)
Porokeratosis palmaris et plantaris disseminata (PPPD)
Linear porokeratosis (LP)
Punctate porokeratosis (PP)

Differentials of linear lesions

# Linear Contact Dermatitis

* Phytophotodermatitis
* Contact allergic or irritant dermatitis
* Artifact or factitial

# Koebner Phenomenon

* Lichen planus
* Psoriasis
* Auto-inoculation: Verruca, Molluscum contagiosum

# Developmental Linear Lesions

* Epidermal nevi
* Incontinentia pigmenti

# Linear Vascular or Lymphatic Lesions

* Thrombophlebitis
* Sporotrichosis
* Coccidioidomycosis

# Linear Lesions of Childhood (

* Porokeratosis
* Lichen striatus
* Epidermal nevi -
o Nevus unis lateris
o Verrucous nevi
* Linear verrucae vulgaris
* Linear lichen planus
* Linear psoriasis
* Incontinentia pigmenti
* Linear morphea
* Erythrokeratoderma variabilis

# Linear - Others not otherwise specified.

* Lichen striatus
* Lichen simplex
* Lichen sclerosus
* Morphea - childhood
* Porokeratosis of Mibelli
* Herpes zoster