Topical Aminolevulinic Acid-Photodynamic Therapy for the Treatment of Acne Vulgaris

Abstract

Light treatments of sebaceous gland disorders with 5-aminolevulinic acid and photodynamic therapy are disclosed. A preferred treatment includes topical application of 5-aminolevulinic acid to the skin followed by light exposures with repeated treatment at various intervals. At low doses of ALA and photodynamic therapy (PDT) in single or multiple treatments, improvement in the sebaceous gland disorder, e.g., acne, provides the discovery that diminishment in sebum secretion and the eradication of bacteria occurs. At high doses of ALA and a single high energy PDT treatment, permanent changes to the sebaceous gland and sebum secretion have been discovered.

1 - 29 . (canceled) 
   
   
       30 . A method for modifying pilosebaceous units, said method comprising the steps of:
 a) topically applying 5-aminolevulinic acid (ALA) to a section of skin of a subject in need of pilosebaceous unit modification, wherein the ALA is compounded to enter the skin and be converted into a photosensitizing agent localized at a pilosebaceous unit and photo-actuable by energy which penetrates outer layers of epidermis; and   b) exposing the section of skin to energy in a range from about 50 J/cm 2  to about 200 J/cm 2  to cause the photosensitizing agent to become photodynamically activated and modify the pilosebaceous unit while not permanently scarring the subject's skin, the pilosebaceous unit being modified for a time period of at least about three weeks after energy exposure.   
   
   
       31 . The method of  claim 30 , wherein the steps of applying and exposing are carried out to modify openings to the infundibulum of pilosebaceous units. 
   
   
       32 . The method of  claim 31 , wherein the steps of applying and exposing are carried out to modify openings to the infundibulum of pilosebaceous units such that the openings' shape is altered to hinder pore pluggage. 
   
   
       33 . The method of  claim 32 , wherein the steps of applying and exposing are carried out to enlarge openings to the infundibulum of pilosebaceous units. 
   
   
       34 . The method of  claim 33 , wherein the steps of applying and exposing are carried out to eliminate pore pluggage from the openings of an infundibulum of the pilosebaceous units. 
   
   
       35 . The method of  claim 30 , wherein the photosensitizing agent is PpIX. 
   
   
       36 . The method of  claim 30 , wherein the steps of applying and exposing are carried out to diminish sebum production. 
   
   
       37 . The method of  claim 30 , wherein the step of applying includes topically applying ALA to a subject having a sebaceous gland disorder. 
   
   
       38 . The method of  claim 30 , wherein the step of exposing includes modifying the pilosebaceous unit for at least about ten weeks after energy exposure. 
   
   
       39 . The method of  claim 30 , wherein the step of exposing includes modifying the pilosebaceous unit for at least about twenty weeks after energy exposure. 
   
   
       40 . The method of  claim 30 , wherein the steps of applying and exposing are repeated a plurality of times. 
   
   
       41 . The method of  claim 30 , wherein the steps of applying and exposing are carried out to decrease the size of sebaceous glands in pilosebaceous units. 
   
   
       42 . The method of  claim 30 , wherein the energy comprises at least one wavelength of electromagnetic radiation in a range between about 550 nm and about 700 nm.