Frequently Asked Questions
Cutaneous Porphyrias
The cutaneous porphyrias present with extreme pain and/or blistering on light-exposed parts of the body. They are:
Some types of acute porphyria (HCP and VP) may also present with blistering.
For in-depth information on living with your porphyria, visit the United Porphyrias Association website.
Sun sensitivity is the main symptom in CEP, EPP, XLP, and PCT. VP and HCP, which are acute porphyrias, can also have blistering sun sensitivity. The degree of sensitivity to sunlight varies considerably. People with sun sensitivity have high levels of porphyrins in the blood plasma which, depending on the type of porphyria, have originated from the liver or the bone marrow. Ultraviolet light interacts with porphyrins in such a way as to damage skin tissue. In general, for people with CEP, EPP, XLP and PCT they should protect themselves from sun exposure. For people with VP and HCP, only if they have sun sensitivity do they need to protect themselves from sun exposure.
Most people with a cutaneous type of porphyria must learn to avoid sunlight as much as possible. Transparent topical sunscreens which block ultraviolet light are ineffective. Physical sunscreens (e.g., zinc oxide) maybe helpful.
Protective clothing may also be recommended.
People with EPP and XLP experience photosensitivity that starts in infancy or early childhood and is characterized by pain, redness, and itching of sun exposed skin. The time after sun exposure to onset of symptoms is variable among people. Variegate porphyria and rarely hereditary coproporphyia (both acute hepatic porphyrias) can also experience photosensitivity that manifests differently than in EPP and XLP and analogously to porphyria cutanea tarda (a hepatic cutaneous porphyria) with skin friability and blistering skin lesions on sun exposed areas.
The photosensitivity in porphyria is to light in the blue-violet spectrum of visible light (VIBGYOR - violet, indigo, blue, green, yellow, orange, red). The peak wavelength for light-mediated porphyrin excitation is ~ 410 nm. Indoor light sources (including lights for surgical or dental procedures) that emit within this spectrum can be problematic.
Yellow filters (which omit wavelengths below ~ 470 nm) can be used to protect people if needed. Fluorescent bulbs have little light within this spectrum and typical LED lights used for lighting purposes also lack within this spectrum.
Avoidance of sun exposure, including through windows, is the most effective way of preventing photosensitivity reactions. Clothing which blocks exposure to visible light may provide some protection as well as hats, gloves, etc.
Monitoring for liver complications is recommended. Treatment of severe liver complications (cholestatic liver failure) requires specialty care at a center with expertise in EPP and XLP and with liver and bone marrow transplant expertise.
Synthesis of vitamin D by the skin in response to exposure to ultraviolet light (in sunlight) is the major source of this vitamin. As a consequence of avoiding sunlight, people are therefore at risk for vitamin D deficiency and may require supplementation.
Mild anemia, with laboratory studies suggestive of iron deficiency, are observed in some people. It remains unknown whether iron therapy improves the anemia in this setting and/or may worsen photosensitivity.
A person's sensitivity to light is dependent on the light quality, the duration of exposure, and individual factors (including geographic latitude and altitude, natural skin pigmentation, and other factors which are not fully understood).
In EPP and XLP, the source of the majority of the phototoxic substances that cause symptoms originate from red blood cells and their parent cells in the bone marrow. Thus, bone marrow transplantation from a donor who lacks EPP or XLP is curative for the recipient. As bone marrow transplantation is associated with significant risk to people (including death and potentially multiple life-altering complications), it is reserved for a very rare subset of people for whom the benefit is thought to out weight the risks of this procedure.
For the acute pain of a severe phototoxic reaction, as may occur in EPP or XLP, the key is avoidance of any further sun or strong light exposure and the use of ice packs/cold compresses on the most severely affected areas of the skin. Some people seem to benefit from a short course of potent, anti-inflammatory medication, such as prednisone or methylprednisolone (Medrol dose pak). Others may derive some benefit from a combination of H1 [diphenhydramine (Benadryl)] and H2- [cimetidine [Tagamet], famotidine (Pepcid)] antihistamine blockers or from combination histamine and serotonin blockade with cyproheptadine [Periactin].