Method for the treatment of acne

1. A method of treating acne in a person in need of such treatment, the method comprising:

applying a photodynamic agent to skin having acne lesions,

wherein the photodynamic agent is aminolevulinic acid hydrochloride,

waiting at least 12 hours during which the skin is not exposed to light, and then

exposing the skin to which the photodynamic agent has been applied to light that causes an activation reaction.

2. The method of claim 1 , wherein the photodynamic agent is an inducer of the synthesis of protoporphyrin IX.

3. The method of claim 1 , wherein the photodynamic agent bypasses the rate limiting step in the production of protoporphyrin IX.

4. The method of claim 3 , wherein the photodynamic agent is aminolevulinic acid.

5. The method of claim 3 , wherein the photodynamic agent is a salt of aminolevulinic acid.

6. The method of claim 3 , wherein the waiting is from 12 to 48 hours.

7. The method of claim 6 , wherein the waiting is from 12 to 36 hours.

8. The method of claim 7 , wherein the waiting is from 18 to 36 hours.

9. The method of claim 8 , wherein the waiting is from 18 to 24 hours.

10. The method of claim 6 , wherein the waiting is from 24 to 36 hours.

11. The method of claim 3 , wherein the light is of a wavelength of from 400 nm to 430 nm.

12. The method of claim 3 , wherein the light is of a wavelength of from 600 nm to 650 nm.

13. The method of claim 3 , wherein the wavelength of light matches the absorption spectrum of protoporphyrin IX.

14. The method of claim 3 , wherein the wavelength of light matches a portion of the absorption spectrum of protoporphyrin IX.

15. The method of claim 3 , wherein the wavelength of light is entirely within the blue region of the spectrum.

16. The method of claim 3 , wherein the skin is exposed to light in the amount of at least 10 Joules/cm 2 .