Diagnosing Sun Sensitivity (Photosensitivity)
What's wrong with me?
You can be sensitive to the sun for a
number of reasons: a disease such as lupus, a photosensitive drug you are
taking, or something in your environment like celery, limes, perfumes, genetics,
and other reasons. Photosensitivity is an abnormal response of the skin to
sun exposure. For example, you get a sunburn in only a very short amount
of time, or your reactions are extreme for the amount of sun exposure.
These are just a few causes of
photosensitivity:
- Solar urticaria
- Systemic lupus erythematosus
- Drug reactions (phototoxic and photoallergy)
- Xeroderma pigmentosum
- Polymorphous light eruption
- Hydroa vacciniforme
- Porphyria
- Hartnup's disease
Links for diagnosing sun sensitivity (photosensitivity)
The Best Practice of Medicine website has several good pages and charts for
determining what can be the cause of why you are sensitive to the sun (photosensitivity).
You may want to print these pages out and take
them with to your doctor.
Other resources for diagnosing sun sensitivity:
Pictures of various sun sensitive conditions
Search using the alphabet for your sun condition. Quite good, many pictures
for some conditions.
DermIS
- Online dermatological atlas
Dermatology Image Atlas - John Hopkins University http://dermatlas.med.jhmi.edu/derm/
University of Iowa: http://tray.dermatology.uiowa.edu/DermImag.htm
What are the statistics of photosensitivity disorders?
A study of 203 patients over a 7.3 year period was conducted. The mean age was
50 years, and 63% of the patients were women.
Most frequent diagnoses (percent of total patients):
- Polymorphous light eruption - (26%)
- Chronic actinic dermatitis ( 17%),
- Photoallergic contact dermatitis (8%),
-
systemic phototoxicity to therapeutic agents (7%),
- and solar urticaria (4%).
Positive photopatch reactions, patch test reactions, or both were observed
in 40 (29%) of the 138 tested patients. The frequencies of the positive
photopatch test reactions were sunscreens (57%), fragrances (18%), and
antimicrobial agents (13%). Of the positive patch test responses, fragrances
elicited 47% of the total positive reactions, followed by sunscreens (39%)
and antimicrobial agents (7%). [J Am Acad Dermatol. 1995 Oct;33(4):597-602. Results of evaluation of 203 patients for photosensitivity in a 7.3-year period. Fotiades J, Soter NA, Lim HW.]
Entrez PubMed
IN WORK
Table 1. Classification of sun related skin conditions (photodermatoses)
Drug photosensitivity:
|
Systemic phototoxicity (caused by ingesting something)
Systemic photoallergy (caused by ingesting something)
Phototoxic contact dermatitis (something contacts the skin)
Photoallergic contact dermatitis (something contacts the skin)
|
| Photo-aggravated skin conditions |
Endogenous eczema
Collagen vascular disease
|
Idiopathic acquired photodermatoses
(Sun related skin conditions from an unknown cause) |
Polymorphic light eruption
Actinic prurigo
Hydroa vacciniforme
Solar urticaria
Chronic actinic dermatitis |
| Genetic & Metabolic
disorders |
Porphyrias
Genodermatoses
o Xeroderma pigmentosum
o Cockayne's syndrome
o Bloom's syndrome
Nutrional deficiencies
o Pellagra
o Hartnup disease [Kwok]
|
References:
[Kwok] Evaluation of A Photosensitive Rash, DR Colin Kwok, NSC Bulletin For Medical Practitioners -> Vol 11 No 1, 2000, National Skin Centre
[National
Skin Center]
[Pediatric] Color Textbook of Pediatric Dermatology
http://www.harcourt-international.com/e-books/viewbook.cfm?ID=227
Photodermatology
and Photodermatoses Chapter 28
| 
