Lichen striatus
- Uncommon
- Children and young adults
- Females > Males if generalized
- Associated with Down syndrome, Crohn’s, atopic dermatitis and congenital megacolon
- Familial form (rare)
- Unknown etiology
- Thought to be a different manifestation to similar triggering factors as lichen planus (for example hepatitis B vaccine)
- Multiple, tiny, discrete, shiny, skin-colored, uniform, pinhead-sized papules ± umbilication, pruritus, Koebner
- Cluster in flexor areas of upper extremities, chest, abdomen, dorsal hands, genitalia >> face, neck, lower extremities, palms, soles, mucous membranes
- Chronic eruption (<1 year)
- Rare oral involvement:
- Soft mucosa: tiny, flat, gray-white papules
- Hard palate/tongue: white plaques
- Nail involvement:
- 10% patients (usually adults)
- Pitting, rippling, longitudinal ridging, terminal splitting, longitudinal linear striations
- Variants:
- Vesicular and hemorrhagic
- Palmoplantar
- Linear
- Follicular spines
- Perforating (associated with lichen planus)
- Generalized (lesions coalesce)
- Actinic (young adults, fitz 4-5)
- Infiltrate of lymphocytes, epithelioid cells ± Langerhans cells, confined between 2-3 dermal papillae 🡪 “ball and claw”
- Overlying atrophic epidermis and thin/absent granular layer
- Central parakeratotic cap
- Vacuolar degeneration ± Max Joseph spaces and colloid bodies
- Melanin incontinence
- Lichen planus
- Guttate lichen sclerosus
- Lichen spinulosus
- Frictional lichenoid dermatitis (elbows and knees)
- Papular eczema
- Verruca plana
- Lichen scrofulosorum
- Lichen striatus
- Papular sarcoidosis
- Lichenoid variant of secondary syphilis
- Spontaneously resolves within 1 year
- Pruritus: topical corticosteroids and oral antihistamines
- Children: topical calcineurin inhibitors
- Generalized disease unresponsive to topical treatment: Narrowband ultraviolet B/Psoralen and ultraviolet A
