Acne is a skin condition that causes pimples to develop. Acne is the most common skin disorder in North America, affecting an estimated 85 percent of adolescents.
Effective acne treatments are available to treat existing pimples and prevent new ones from developing. In addition, cosmetic treatments can help to reduce scarring and changes in skin color caused by acne.

HOW DOES ACNE DEVELOP? — There are four basic events involved in the development of acne lesions.

Hair follicles become blocked with an overabundance of normal skin cells. These cells combine with sebum (an oily substance that lubricates the hair and skin), creating a plug in the follicle.

The glands that produce sebum, known as sebaceous glands, enlarge during adolescence and sebum production increases. Numerous sebaceous glands are found on the face, neck, chest, upper back, and upper arms.

The increase in sebum production allows for the overgrowth of a bacterium called Cutibacterium (formerly Propionibacterium) acnes that normally lives on the skin.

Inflammation occurs as a result of bacterial overgrowth or other factors. This can lead to the rupture of the follicle and the formation of a red or tender pimple.


Hormonal changes — Hormonal changes during adolescence cause the sebaceous glands to become enlarged, and sebum production increases. In most people with acne, hormone levels are normal, but the sebaceous glands are highly sensitive to the hormones.

Less often, women’s hormone levels are affected by an underlying medical problem known as polycystic ovary syndrome (PCOS).

Acne tends to resolve between ages 30 to 40, although it can persist into or develop for the first time during adulthood. Post-adolescent acne predominantly affects women, in contrast to adolescent acne, which predominantly affects men. Acne can flare before a woman’s menstrual period, especially in women older than 30 years.

External factors — Oil-based cosmetics may contribute to the development of acne. Oils and greases in hair products can also worsen skin lesions. Water-based or “noncomedogenic” products are less likely to worsen acne.

People with acne often use soaps and astringents. While these treatments remove sebum from the skin surface, they do not decrease sebum production; frequent or aggressive scrubbing with these agents can actually worsen acne.

Diet — The role of diet in acne is controversial. Some studies have found weak associations between cow’s milk and an increased risk of acne, perhaps because of hormones that occur naturally in milk. However, there is no strong evidence that milk, high-fat foods, or chocolate increase the risk of acne.

Stress — Psychological stress can probably worsen acne. In several studies of students, acne severity appeared to worsen during times of increased stress.

ACNE TREATMENT — There is no single best treatment for acne, and combinations of treatments are sometimes recommended. Since acne lesions take at least eight weeks to mature, you should use a treatment for a minimum of two to three months before deciding if the treatment is effective.

Acne skin care — Skin care is an important aspect of acne treatment.

Skin hygiene — Wash your face no more than twice daily using a gentle nonsoap facial skin cleanser (eg, Cetaphil, Oil of Olay bar or foaming face wash, or Dove bar) and warm (not hot) water. Some providers recommend avoiding use of a washcloth or loofah, and instead using the hands to wash the face. Vigorous washing or scrubbing can worsen acne and damage the skin’s surface.

Do not pick or squeeze pimples because this may worsen acne and cause skin swelling and scarring. It can also cause lesions to become infected.

Moisturizers — Use of a moisturizer minimizes dryness and skin peeling, which are common side effects of some acne treatments. Moisturizers that are labeled as “noncomedogenic” are less likely to block skin pores.

Sun protection — Some acne treatments increase the skin’s sensitivity to sunlight (eg, retinoids, doxycycline). To minimize skin damage from the sun, avoid excessive sun exposure and use a sunscreen with SPF 30 or higher that is broad spectrum (blocks both UVA and UVB light) before sun exposure.

Can I treat my own acne? — If you have mild acne, you can try to treat yourself with nonprescription products initially. Nonprescription acne treatments may include salicylic acid, benzoyl peroxide, sulfur, alpha hydroxy acids, adapalene, or tea tree oil, all of which are available in nonprescription strengths. A combination of these treatments may be more effective than using one single product alone. In rare cases, people have a severe allergic reaction to acne products, so for the first three days, try them on just a small area.

If you do not improve after three months of using nonprescription products or you have moderate or severe acne, consult a healthcare provider for advice on the most effective treatments.

Noninflammatory acne — Noninflammatory acne causes whiteheads or blackheads without redness or skin swelling.

Retinoids — Topical retinoid medications are often recommended for noninflammatory acne. Examples of these medications include tretinoin (Retin-A, Avita, Atralin) and tazarotene (Tazorac), which require a prescription, and adapalene (Differin), which is available both by prescription and over the counter.

Retinoids are usually applied once per day, although people who develop skin irritation can reduce this to every other day or less, then increase as tolerated over time. Most people become more tolerant of retinoids over time.

Most retinoids are available in a gel or cream. People with oily skin may prefer gels because they have a drying effect, while people with dry skin may prefer a cream.

Retinoids can cause skin irritation. While using topical retinoids, you should apply a sunscreen with SPF 30 or greater before sun exposure.

Other acne products — People who cannot tolerate retinoids may try other topical medications, such as salicylic acid, glycolic acid, or azelaic acid (Azelex, Finacea). All of these treatments can be helpful in reducing noninflammatory acne, and azelaic acid may reduce acne-related darkening of skin.

Mild to moderate inflammatory acne — Mild to moderate acne with some inflammation is usually treated with topical retinoids, topical antibiotics, or benzoyl peroxide.

A combination of medications, usually benzoyl peroxide with a topical antibiotic and/or retinoid (eg, tretinoin), is more effective than treatment with one agent alone.

Benzoyl peroxide — Benzoyl peroxide is usually applied twice per day. It may be combined with a topical retinoid, in which case the benzoyl peroxide is applied in the morning and the retinoid is applied at night. Benzoyl peroxide can irritate the skin, sometimes causing redness and skin flaking, and it can bleach clothing, towels, bedding, and hair.

Topical antibiotics — Topical antibiotics (creams or liquids) control the growth of acne bacteria and reduce inflammation. Topical antibiotics include erythromycin, clindamycin, sulfacetamide, and dapsone.

Moderate to severe inflammatory acne — For people with moderate to severe inflammatory acne, oral antibiotics or an oral retinoid known as isotretinoin (Amnesteem, Claravis, Sotret, Absorica) may be recommended. Topical medication may be used in combination with oral antibiotics.

Women often benefit from hormonal treatment with a birth control pill.

Oral antibiotics — Oral antibiotics work to slow the growth of acne-producing bacteria. However, oral antibiotics can have bothersome side effects, including vaginal yeast infections in women and stomach upset.

Doxycycline and minocycline are the most commonly prescribed oral antibiotics for acne. They cannot be used during pregnancy or in children less than nine years of age.

Oral isotretinoin — Oral isotretinoin is a potent retinoid medication that is extremely effective in the treatment of severe acne. It cures or significantly improves acne in the majority of patients. Oral isotretinoin is effective in treating the most disfiguring types of acne.

Oral isotretinoin is usually taken in pill form once or twice daily with food for 20 weeks, then stopped. In some cases, acne can initially worsen before it improves. To reduce the risk for this initial flare of acne, isotretinoin is sometimes given at a lower dose for the first month of treatment. After treatment is stopped, improvement can continue for up to five months.

Side effects and risks — Despite its positive effects, oral isotretinoin can have serious side effects and should be used with caution. Taking isotretinoin during pregnancy can cause miscarriage and life-threatening malformations in the baby. For these reasons, there are strict rules in the United States for healthcare providers, pharmacists, and patients regarding the use and prescription of oral isotretinoin. Prescriptions of isotretinoin are regulated by the iPLEDGE program (, which requires the following:

All women must have two negative pregnancy tests before receiving a prescription, and then they must have monthly pregnancy tests throughout the course of treatment.

Women who could become pregnant must fill their prescription within seven days of receiving it; after this time, a new prescription must be written.

Any woman who is or might become sexually active with a male partner must use two forms of birth control for at least one month before starting therapy and continue until one month after stopping isotretinoin.

A variety of nonpregnancy related side effects may occur during isotretinoin therapy:

Dryness or peeling of skin, soreness and cracking of the lips, itching, muscle pain, nosebleeds, difficulty wearing contact lenses, and sensitivity to the sun may occur during treatment.

There is concern about the relationship between isotretinoin and depression and suicidal behavior. While there is not enough evidence to conclude that it causes depression or suicidal behavior, patients taking isotretinoin should report any sadness, depression, or anxiety to their healthcare provider.

Isotretinoin can cause increases in blood levels of triglycerides (fatty substances related to cholesterol), liver damage, pancreatitis, and changes in the blood counts. It is unclear whether isotretinoin treatment increases the risk for inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease.

While many of these side effects can be managed without stopping the drug, others can be dangerous and require that you immediately stop taking it. Stay in touch with your doctor, and follow instructions for getting regular blood tests to monitor cholesterol, triglycerides, liver function, and blood counts.

Hormone therapy — The hormone estrogen can help to offset the effect of androgens (hormones responsible for acne development). Estrogen treatment in the form of a birth control pill is sometimes recommended for women with moderate or severe acne.

Not all oral contraceptives should be used for the treatment of acne; some can actually worsen acne. Certain types of intrauterine devices (IUDs) and some injectable forms of birth control also may worsen acne. Discuss the best options with your healthcare provider.

Spironolactone is another medication that can be used to treat acne in women. Spironolactone reduces the effects of androgens.

The benefits of birth control pills and other hormonal medications may not be noticeable until three to six months after treatment is started. Treatment with hormonal medications is not recommended during pregnancy.

Acne and pregnancy — Many acne treatments are not safe for use during pregnancy. Women who are pregnant or intending to become pregnant should consider stopping all acne treatments before becoming pregnant. If acne therapy becomes necessary, discuss the options with your healthcare provider.


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Influenza symptoms and treatment

INTRODUCTION — Influenza (commonly called the flu) is a highly contagious illness that can occur in children or adults of any age. It occurs more often in the winter months because people spend more time in close contact with one another. The flu is spread easily from person to person by coughing, sneezing, or touching surfaces.

Every year, complications of the flu require more than 200,000 people in the United States to be hospitalized. Serious illness is more likely in the very young, older adults, pregnant women, and people who have certain health problems such as asthma or other forms of lung disease.

There have been several widespread flu outbreaks (called pandemics), which led to the deaths of many people worldwide. These outbreaks occurred when new strains of influenza viruses formed (often from pigs or birds) and humans became infected because they had no immunity to these viruses.

This article discusses the symptoms and treatment of seasonal, swine H1N1, and avian flu. Treatments to prevent the flu, including the flu shot, are discussed separately.

FLU SYMPTOMS — Symptoms of seasonal flu can vary from person to person but usually include:

Fever (temperature higher than 100ºF, or 37.8ºC)

Headache and muscle aches


Cough and sore throat may also be present

People with the flu usually have a fever for two to five days. This is different than fever caused by other upper respiratory viruses, which usually resolve after 24 to 48 hours.

Most people with the flu have fever and muscle aches, and some people also have cold-like symptoms (runny nose, sore throat). Flu symptoms usually improve over two to five days, although the illness may last for a week or more. Weakness and fatigue may persist for several weeks

Flu complications — Complications of influenza occur in some people; pneumonia is the most common complication. Pneumonia is a serious infection of the lungs and is more likely to occur in young children, people over the age of 65, people who live in long-term care facilities (nursing homes), and those with other illnesses such as diabetes or conditions affecting the heart or lungs. Pneumonia is also more common in people with weakened immune systems, such as those who have had a transplant.

FLU DIAGNOSIS — Influenza is usually diagnosed based on symptoms (fever, cough, and muscle aches). Lab testing for influenza is performed in certain cases, such as during a new influenza outbreak in a community and in patients who are at increased risk for complications.


When to seek help — Most people with the flu recover within one to two weeks without treatment. However, serious complications of the flu can occur. Call your doctor or nurse immediately if:

You feel short of breath or have trouble breathing

You have pain or pressure in your chest or stomach

You have signs of being dehydrated, such as dizziness when standing or not passing urine

You feel confused

You cannot stop vomiting or you cannot drink enough fluids

In children, you should seek help if the child has any of the above or if the child:

Has blue or purplish skin color

Is so irritable that he or she does not want to be held

Does not have tears when crying (in infants)

Has a fever with a rash

Does not wake up easily

There are several groups of people who are at increased risk for flu complications. These include pregnant women, young children (<5 years of age and especially <2 years of age), people ≥65 years of age, and people with certain diseases such as chronic lung disease (such as asthma), heart disease, diabetes, immunosuppressing conditions (such as HIV infection or transplantation), and some other diseases. If you or your child has flu symptoms and is at increased risk for flu complications, you should call your health care provider.

Treat symptoms — Treating the symptoms of influenza can help you to feel better but will not make the flu go away faster.

Rest until the flu is fully resolved, especially if the illness has been severe.

Fluids – Drink enough fluids so that you do not become dehydrated. One way to judge if you are drinking enough is to look at the color of your urine. Normally, urine should be light yellow to nearly colorless. If you are drinking enough, you should pass urine every three to five hours.

Acetaminophen (sample brand name: Tylenol) can relieve fever, headache, and muscle aches. Aspirin and medicines that include aspirin (eg, bismuth subsalicylate [sample brand name: Pepto-Bismol]) are not recommended for children under 18 because aspirin can lead to a serious disease called Reye syndrome.

Cough medicines are not usually helpful; cough usually resolves without treatment. We do not recommend cough or cold medicine for children under age 6 years.

Antiviral treatment — Antiviral medicines can be used to treat or prevent influenza. When used as a treatment, the medicine does not eliminate flu symptoms, although it can reduce the severity and duration of symptoms by about one day. Not every person with influenza needs an antiviral medicine, but some people do; the decision is based upon several factors. If you are severely ill and/or have risk factors for developing complications of influenza, you will need an antiviral agent. People who are only mildly ill and have no risk factors for complications are usually treated with an antiviral medicine if they have had symptoms for 48 hours or less, but they are not treated if they have had symptoms for more than 48 hours.

Antiviral medicines that are used to treat the flu include oseltamivir (brand name: Tamiflu), zanamivir (brand name: Relenza), peramivir (brand name: Rapivab), and baloxavir (brand name: Xofluza). Antiviral treatment is most effective for seasonal influenza when it is taken within the first 48 hours of flu symptoms.

The best antiviral medicine depends upon the type of influenza virus, if the virus could be resistant, and some individual factors. A doctor or nurse should make this decision.

Side effects — Zanamivir and oseltamivir can cause mild side effects, including nausea and vomiting; zanamivir, which is inhaled, can cause difficulty breathing in some cases. Diarrhea is the most common side effect of peramivir and baloxavir. Most people are able to continue the medicine despite the side effects.

Antibiotics — Antibiotics are NOT useful for treating viral illnesses such as influenza. Antibiotics should only be used if there is a bacterial complication of the flu such as bacterial pneumonia, ear infection, or sinusitis. Antibiotics can cause side effects and lead to development of antibiotic resistance.

Complementary and alternative treatments — There are a wide variety of herbal, homeopathic, and other complementary and alternative treatments that are marketed for influenza. Unfortunately, there have been few well-designed studies to evaluate their efficacy and safety.

PREVENTING FLU — Treatments to prevent influenza are discussed separately.

SWINE H1N1 FLU — A new strain of H1N1 influenza, which contains parts of swine, avian, and human influenza viruses, was first seen in humans in March 2009 in Mexico. Human infections subsequently occurred around the world and caused a pandemic that continued until August 2010. The same strain of H1N1 influenza has since become one of the strains of seasonal influenza.

Symptoms of infection with the swine H1N1 flu virus and treatment for it were generally similar to those of seasonal flu.

AVIAN FLU — Avian influenza (bird flu) is caused by strains of influenza virus that originally infected birds. Infected birds include chickens, ducks, and geese, among others.

There are several strains of avian flu; the H5N1 avian flu virus is the cause of concern since it has led to several deaths in people, mostly in Asia. Another type of avian flu that causes illness in people is called H7N9. To date, avian flu has primarily spread from bird to bird and much less commonly from bird to human; human-to-human transmission has occurred rarely. Most humans who became infected with avian flu had direct contact with sick or dead poultry or wild birds or had very recently visited a live poultry market. No human cases of avian influenza have been described in the United States or elsewhere in North America.

Avian flu is frequently severe, and there is little natural immunity in the human population. At least one antiviral medicine (oseltamivir) might improve the chance of surviving the infection.

There is a vaccine to prevent H5N1 avian flu. The vaccine is not commercially available but has been stockpiled by the United States government in case it is needed in the future.


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