Photodynamic therapy of skin lesions

Photodynamic therapy (PDT) is gaining acceptance as a convenient and relatively complication-free method of treating precancerous skin lesions on the face. These lesions, known as actinic keratoses (AKs), are primarily caused by damage from UV radiation from the sun. If left untreated, some of these AKs will eventually develop into squamous cell cancer (SCC). PDT, application of a chemotherapy cream (5-FU), and cryotherapy (freezing) are all effective methods of treating AKs in order to prevent the development of SCC.

How does PDT work? PDT, also known as ALA/PDT, involves the use of a photosensitizing drug (one that becomes active when exposed to light) along with a light source. In the U.S., the most common photosensitizing drug for this purpose is aminolevulinic acid (ALA) which is marketed under the trade name Levulan®. When applied to the face and absorbed by AK cells, the precancerous cells become highly sensitive to light. With exposure to FDA-approved light sources (Blu-U and ClearLight) a reaction occurs that destroys the AK cells.

What does a typical PDT session involve? PDT for sun-damaged facial skin is performed on an outpatient basis and usually requires only one treatment session. A typical treatment session involves the following steps:

1. The face is rigorously cleaned with alcohol or acetone in order to remove oil from the skin.
2. The photosensitizing medication (ALA) is applied to the entire face and up to an hour is allowed for the medication to "activate" the skin lesions.
3. Following an incubation period the treated skin is exposed to the light source for around 17 minutes.
4. After treatment, it is recommended to avoid exposure to sunlight for up to 48 hours.

What are potential after effects of PDT? During treatment, most patients experience sensations of heat, tingling, or burning. An expected after effect of PDT is redness of the skin similar to sunburn. In some instances, temporary blistering and severe pain may occur. The skin appearance returns to normal within 2 to 3 weeks.

Are there other benefits to PDT? Following treatment, aging-related skin damage such as skin lines and blotchy pigmentation may also be improved. While used primarily for treating sun-damaged skin, PDT is used for other skin conditions, such as acne and rosacea. Additionally, PDT is starting to be used in the treatment of certain cancers, even those involving internal organs, such as the esophagus and lung.

What are the alternatives to PDT? PDT is the relative "new kid on the block" in the treatment of sun-damaged facial skin. Prior to its introduction, most AKs were treated individually with cryotherapy (freezing) or with the topical application of a chemotherapy medication, 5-flurouracil (5-FU). A drawback to cryotherapy is that only visible AKs can be treated. With PDT, even those AKs that have not yet progressed to the point of being seen are addressed. Topical chemotherapy treatment for AKs involves daily applications for weeks and can be associated with severe skin reactions.

The number of skin cancers related to sun exposure has increased annually for many years. PDT is emerging as an important modality to treat precancerous AKs in order to prevent the development of many of these cancers. Advantages of topical PDT are that the method is non-invasive, effective, and generally gives a good cosmetic outcome.

Could I be Depressed?

The diagnosis of depression includes several subgroups including major depression, dysthymia and minor depression. Taking these three entities into consideration, it has been estimated that as many as one-in-five patients seen in primary care offices are depressed.
The diagnosis of major depression is based on exhibiting five or more of the following symptoms for a period of at least 2 weeks:

• Low or irritable mood most of the time
• A loss of pleasure in usual activities
• Trouble sleeping or sleeping too much
• A big change in appetite, often with weight gain or loss
• Tiredness and lack of energy
• Feelings of worthlessness, self-hate, and
  guilt
• Difficulty concentrating
• Slow or fast movements
• Lack of activity and avoiding usual activities
• Feeling hopeless or helpless
• Repeated thoughts of death or suicide

Dysthymia, sometimes considered to be “chronic depression” has symptoms that are less severe than major depression but may have been present for a much longer period of time. Minor depression is similar to major depression except it only has two to four of the symptoms mentioned above.
In spite of how common depression is in the general population, it frequently goes undetected and untreated. The U.S. Preventive Services Task Force (USPSTF) has found that screening performed during doctor’s visits increases the identification of depressed individuals.
A number of different screening tests for depression are used by doctors in the primary care setting. Most of these are self-administered, meaning that the patient completes a questionnaire that asks about various symptoms and physical signs that could indicate depression. Specific tests, such as the Beck Depression Inventory and the Zung Self-Rating Depression Scale, include around 20 questions and are “graded” in order to determine if depression is present, and if so, how severe is it.
More recently, a 2-question depression screening tool was found to have close to the same accuracy as the more extensive questionnaires. Answering “yes” to both of the following questions about mood and pleasure from activities usually found to be enjoyable makes the diagnosis of depression likely:

1. "Over the past 2 weeks, have you felt down, depressed, or hopeless?"
   
2. "Over the past 2 weeks, have you felt little interest or pleasure in doing things?"

This 2-question tool is felt to have fairly good sensitivity (correctly identifying people with depression) but only fair specificity (correctly identifying people who aren’t depressed). In other words this screening test did a good job of detecting people who were truly depressed but tended to over diagnose those in whom depression was not a significant issue. For this reason, when the answers to both questions suggest that someone is depressed, a more formal psychological investigation is needed.
Physical problems are not the only reason for seeing the doctor. If you recognize several of the depression symptoms mentioned above or answer “yes” to the 2-question screening test, a visit to your doctor to discuss your feelings is in order. In addition to advising screening for the depression, the USPSTF also found that treating depressed adults with antidepressants, psychotherapy, or both is effective in reducing symptoms and improving productivity. Large-scale studies have, in fact, shown that following initiation of treatment approximately two thirds of individuals achieve remission from their depression within a year.

Need Another Reason to Stop Smoking?

The percentage of US adults who smoke cigarettes has been decreasing over the past several decades. In 1965 approximately 42% of adults smoked cigarettes as compared to 18% today. In spite of warnings regarding health risks associated with smoking, however, nearly 42 million adults and over 3.5 million middle and high school students continue to smoke cigarettes.
If the well-known increased risk of developing lung cancer and coronary heart disease wasn’t enough to convince smokers to stop, new information released by the US Surgeon General should be of concern to the most ardent smokers. In the 2014 Surgeon General's Report, The Health Consequences of Smoking—50 Years of Progress, an expert panel found that there was sufficient evidence to confirm that cigarette smoking was a cause for the following diseases:

• Colorectal Cancer – Most colon cancer starts from pre-cancerous polyps. It has been confirmed that such polyps could develop as a result of smoking.
  
• Chronic Obstructive Pulmonary Disease (COPD) – For some time, smoking has been a known cause for the development of COPD (emphysema). This report went one step further, however, in identifying cigarette smoking as the dominant cause of COPD among men and women in the US.
  
• Liver Cancer— A causal relationship between smoking and the development of hepatocellular carcinoma (liver cancer) was confirmed.
  
• Congenital Malformations – Cigarette smoking during early pregnancy was found to be a cause for the development of cleft palates.
• Male Sexual Dysfunction – Smoking was found to be a cause for erectile dysfunction in men.
  
• Diabetes – The risk of developing diabetes was found to be 30–40% higher for active smokers than nonsmokers. Also, the likelihood of developing diabetes increased along with the number of cigarettes smoked.
  
• Eye Disease – A causative link between cigarette smoking and macular degeneration, a leading cause of vision loss in Americans 60 and older, was confirmed.
  
• Rheumatoid Arthritis (RA) – Some cases of RA are caused by cigarette smoking-related impairment of immune system function.

In addition to the diseases in which cigarette smoking was considered to be the causative, the report noted a number of other health issues which have been linked, but not proven to be caused, by cigarette smoking including:

• Dental cavities
  
• Miscarriage
  
• Attention deficit hyperactivity disorder among children
  
• Asthma
  
• Breast Cancer
  
• Idiopathic pulmonary fibrosis.
  
• Inflammatory Bowel Disease (Crohn's Disease)

Unfortunately, even non-smokers are at risk of developing certain diseases as a result of exposure to secondhand smoke. The report noted that secondhand smoking increases the risk of someone having a stroke by 20-30%. Additionally, the annual cost attributed to lost productivity from premature death due to exposure to secondhand smoke was estimated to be around 5 billion dollars.
Hopefully, information from this report along with ongoing government-sponsored efforts, such as smoke-free indoor air policies and funding statewide tobacco control programs, will help to achieve the goal of a smoke-free America.