BASICS
DESCRIPTION
- A disorder of keratinization
- Lesions of the skin with conical papules of a red and brown color surrounding the hair follicle
- Edges may become raised over time (1).
- Typically found in 30 to 40 year olds (2)
- Commonly located on the arms and legs
ETIOLOGY AND PATHOPHYSIOLOGY
Proliferation of atypical keratinocytes from a mutant clonal cell line
Genetics
- Genetic studies have reveled mutation of MVK (3).
- Mutation of keratinocyte proliferation and differentiation (3)
- Autosomal dominant with variable penetrance (1)
RISK FACTORS
- UV-light exposure (2)
- Male sex (1)
- Immune suppression (1)
- Infection (1)
GENERAL PREVENTION
Sunscreen and avoidance of UV exposure (2)
COMMONLY ASSOCIATED CONDITIONS
Skin malignancies in up to 10% of people (1)
DIAGNOSIS
HISTORY
- Onset in the 30 to 40s
- Family history of similar lesions
- May be pruritic
PHYSICAL EXAM
- Sun exposed areas with hyperkeratotic papules, patches, or plaques surrounded by a thin-lined elevated border
- Palms and soles are spared.
DIFFERENTIAL DIAGNOSIS
- Disseminated actinic keratosis
- Actinic keratosis
- Nevoid basal cell syndrome
- Lichen nitidus
- Dermal duct nevus
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
- Biopsy with confirmation by histology
- Cornoid lamella in the epidermis with absent granular layer under the parakeratotic column
Follow-Up Tests & Special Considerations
Regular skin exams to monitor for malignant changes
TREATMENT
GENERAL MEASURES
No controlled studies exist as yet to evaluate treatment modality.
MEDICATION
First Line
- Diclofenac sodium 3% topical: Apply to lesions twice daily for 60 to 90 days (4)[C].
- This topical medication is supported by best available case study evidence as compared with other medications.
Second Line
- 5-florouracil 5% topical: Apply to lesions twice daily for 2 to 6 weeks (4)[C].
- Topical imiquimod 5% topical cream: Apply to defined lesions 2 times per week at bedtime for 16 weeks; and leave on skin for 8 hours (4)[C].
- Tretinoin (50 years and younger): Apply 0.05% cream to lesions once daily at bedtime (4)[C]
- Vitamin D3 analogs (Tacalcitol) ointment 0.0002-0.0004% once or twice a day for up to 4 weeks (4)[C]
- Second-line treatment options are separated based on a lack of high quality evidence.
ADDITIONAL THERAPIES
Cosmetic cover-up with tinted creams or spray tans.
SURGERY/OTHER PROCEDURES
- Photodynamic therapy (4)[C]
- Cryotherapy (4)[C]
- Laser therapy (4)[C]
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Yearly dermatologic examination
PATIENT EDUCATION
Avoidance of UV exposure
PROGNOSIS
Excellent
REFERENCES
11 Torkamani N, Sinclair R. Disseminated superficial actinic porokeratosis accentuated by spray tan. Int J Dermatol. 2015;54(12):e545-e546.22 Rouhani P, Fischer M, Meehan S, et al. Disseminated superficial actinic porokeratosis. Dermatology Online J.. 2012;18(12):24. http://escholarship.org/uc/item/66j9q5jh.33 Zhou MS, Xie HF, Chen ML, et al. A novel mutation for disseminated superficial actinic porokeratosis in the MVK gene. Br J Dermatol. 2014;171(2):427-429.44 Skupsky H, Skupsky J, Goldenberg G. Disseminated superficial actinic porokeratosis: a treatment review. J Dermatolog Treat. 2012;23(1):52-56.
CODES
ICD10
Q82.8 Other specified congenital malformations of skin
ICD9
692.75 Disseminated superficial actinic porokeratosis (DSAP)
SNOMED
Disseminated superficial actinic porokeratosis (disorder)
CLINICAL PEARLS
Age- and UV-related nonmalignant skin condition