This woman presented with an inflamed, extremely pruritic, patterned rash on her arm approximately three days after having what she was told to be a “henna tattoo” placed on her arm at a kiosk at a local shopping mall.
What is your diagnosis?
Diagnosis: Allergic contact dermatitis to p-Phenylenediamine.
Discussion: Phenylenediamine is a common dye found in many hair coloring products. Many people who apply decorative temporary tattoos use hair dye and claim that it gives a “henna-like” result. Phenylenediamine hair dye is used because is readily available and inexpensive.
Figure 2. shows a temporary tattoo made from Phenylenediamine 2 weeks after application (note no reaction, it will fade/wash off over next 2 weeks).
Figure 3. shows that patient’s patch test (T.R.U.E. Test) results at 48 hours with a 2+ - (borderline) 3+ reaction to p-Phenylenediamine, confirming the diagnosis of allergic contact dermatitis.
Treatment: I treated her with a topical class 1 steroid and doxepin 5% spray. The patient called three days after treatment initiation and reported significant improvement and relief.
We will follow up in approximately 8 weeks to address any postinflammatory hyperpigmentation/dyschromia, as needed.