Forget the Oscars. The American Contact Dermatitis Society has just held its annual red carpet event — allergens of the year. The winner for the 2008 Allergen of the Year is … nickel. Read more…
I seemed to have a run on psoriasis patients this week. It is not surprising; psoriasis is often worse in the winter when the air is dry and when there is less sunlight. Both warm humid air and sunlight will improve psoriasis.
If you have psoriasis, please visit the National Psoriasis Foundation site –it’s an excellent resource about psoriasis and its treatments. They will also help you find a dermatologist in your area who treats psoriasis!
See also: Severe Psoriasis Linked to Increased Risk of Death
Photo of psoriasis from University of Manchester School of Medicine website.
A patient of mine presented last week with an itchy tattoo. He had been on a cruise and had this temporary henna tattoo placed on his right arm. A few days later when everyone else’s tattoos were fading, his got darker and became itchy. The redness and itching became much worse over the next week. What happened?
My patient is allergic to para-phenylenediamine (PPD).
PPD is a coloring that is used in permanent hair dyes. It is also sometimes added to henna to create a dark color, or “black henna,” for temporary tattoos.
Contact dermatitis is a delayed type hypersensitivity reaction; it’s the same type of allergy that occurs after exposure to poison ivy or poison oak. It takes 1-2 days to develop the rash from an allergen, and the response can last weeks.
If you are allergic to hair dye, then you should be weary of getting a henna tattoo. PPD can also been found in printer inks, black rubber, and photodevelopers.
What is more problematic (especially for those studying for the derm boards) is that PPD can cross-react with sundry other things, causing an identical allergic reaction. These include PABA sunscreens, azo dyes (found in fabrics), benzocaine anesthetics, and sulfa drugs.
My patient was treated with topical corticosteroids and the itchy rash resolved. Some patients actually need oral steroids to treat this; consult your physician if you think you are having an allergic reaction to your tattoo.
And don’t get a tattoo that you wouldn’t want your dermatologist (or mother) to see.
Do you have a chronic, itchy rash?
For most patients in winter, eczema is the result of dry, cold air — a condition called asteatotic eczema. It is common and can occur in people from Boston to San Diego.
For some elderly patients, however, chronic eczema can be caused by a blood pressure medication. A new study from the Journal of Investigative Dermatology found that patients on calcium channel blockers (CCBs) were more likely to have eczema than those who were not taking these blood pressure pills. They also found that the skin rash resolved in 68% of patients who stopped their CCB.
Blood pressure pills should never be changed without consulting your physician. If you have a skin rash and are on a CCB, then discuss this with your physician.
Calcium channel blocker (CCB) medications include nifedipine (Adalat, Procardia), nicardipine (Cardene), bepridil (Vascor), isradipine (Dynacirc), nimodipine (Nimotop), felodipine (Plendil), amlodipine (Norvasc), diltiazem (Cardizem), and verapamil (Calan, Isoptin).
