Phytophototoxin Poisoning Workup

Updated: Apr 20, 2015
  • Author: Toluwumi Jegede, MD; Chief Editor: Asim Tarabar, MD  more...
  • Print
Workup

Laboratory Studies

Phytophotodermatitis (PPD) is a clinical diagnosis. No serum level assay for psoralens is available or appropriate. Clinical presentation is delayed, and systemic clearance of psoralens is complete. Laboratory data (eg, porphyrin levels) may be obtained to exclude other diagnoses.

Next:

Other Tests

With yeast inhibition technique, plant extract is used to evaluate for presence of psoralens.

In individuals in whom the diagnosis is in question, referral to a dermatologist for photopatch testing may be warranted. Testing should include pesticides, and plant allergens.

Previous
Next:

Procedures

In individuals in whom the diagnosis is in question, referral to a dermatologist for a skin biopsy may be warranted. A skin biopsy may demonstrate epidermal hyperkeratosis, necrotic keratinocytes, "sunburn cells," epidermis spongiosus, and an inflammatory cell infiltrate. An increase in melanocytes is seen. [27]

A photopatch test may be useful if the clinical picture does not clearly suggest phototoxicity rather than photoallergy.

Previous