Dermatol Ther. 2003;16(3):195-205
Cutaneous infections in the elderly: diagnosis and management
Weinberg JM, Scheinfeld NS
Department of Dermatology, St. Luke's-Roosevelt Hospital Center, and Beth Israel Medical Center, New York, New York.

Over the past several years there have been many advances in the diagnosis and treatment of cutaneous infectious diseases. This review focuses on the three major topics of interest in the geriatric population: herpes zoster and postherpetic neuralgia (PHN), onychomycosis, and recent advances in antibacterial therapy. Herpes zoster in adults is caused by reactivation of the varicella-zoster virus (VZV) that causes chickenpox in children. For many years acyclovir was the gold standard of antiviral therapy for the treatment of patients with herpes zoster. Famciclovir and valacyclovir, newer antivirals for herpes zoster, offer less frequent dosing. PHN refers to pain lasting >/=2 months after an acute attack of herpes zoster. The pain may be constant or intermittent and may occur spontaneously or be caused by seemingly innocuous stimuli such as a light touch. Treatment of established PHN through pharmacologic and nonpharmacologic therapy will be discussed. In addition, therapeuti c strategies to prevent PHN will be reviewed. These include the use of oral corticosteroids, nerve blocks, and treatment with standard antiviral therapy. Onychomycosis, or tinea unguium, is caused by dermatophytes in the majority of cases, but can also be caused by Candida and nondermatophyte molds. Onychomycosis is found more frequently in the elderly and in more males than females. There are four types of onychomycosis: distal subungual onychomycosis, proximal subungual onychomycosis, white superficial onychomycosis, and candidal onychomycosis. Over the past several years, new treatments for this disorder have emerged which offer shorter courses of therapy and greater efficacy than previous therapies. The treatment of bacterial skin and skin structure infections in the elderly is an important issue. There has been an alarming increase in the incidence of gram-positive infections, including resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and drug-resistant pneumococci. While vancomycin has been considered the drug of last defense against gram-positive multidrug-resistant bacteria, the late 1980s saw an increase in vancomycin-resistant bacteria, including vancomycin-resistant enterococci (VRE). More recently, strains of vancomycin-intermediate resistant S. aureus (VISA) have been isolated. Gram-positive bacteria, such as S. aureus and Streptococcus pyogenes are often the cause of skin and skin structure infections, ranging from mild pyodermas to complicated infections including postsurgical wound infections, severe carbunculosis, and erysipelas. With limited treatment options, it has become critical to identify antibiotics with novel mechanisms of activity. Several new drugs have emerged as possible therapeutic alternatives, including linezolid and quinupristin/dalfopristin.

GENERIC NAME: acyclovir
BRAND NAME: Zovirax

DRUG CLASS AND MECHANISM: Viral illnesses differ from bacterial infections in that viruses are not living organisms, but rather take over living cells and reproduce themselves, often at the expense of the host cell. Acyclovir is an antiviral drug which acts against the Herpes viruses, including herpes simplex 1 and 2 (cold sores and genital herpes), varicella-zoster (shingles and chicken pox), and the Epstein-Barr virus (mononucleosis). Acyclovir inhibits the replication of viral DNA needed to reproduce itself. Virally infected cells absorb more acyclovir than normal cells and convert more of it to an active form which prolongs its antiviral activity where it is most needed.

PREPARATIONS: Capsules (200 mg); Tablets (400mg, 800mg); Ointment 5% (15gm).

STORAGE: Acyclovir should be stored at room temperature in a tight container.

PRESCRIBED FOR: Oral acyclovir is used to treat initial genital herpes infections and to treat patients with recurrent (6 episodes per year) severe genital herpes. Acyclovir reduces the pain and the number of lesions in the initial case, and decreases the frequency and severity in those with recurrent infections. In the treatment of shingles, acyclovir reduces pain, shortens the healing time, and limits the spread of virus and the formation of new lesions. Acyclovir can be used to treat chicken pox and acts to reduce healing time, limit the number of lesions, and reduce fever if used within the first 24 hours after the onset of the disease. Acyclovir ointment is used topically to treat initial genital herpes where it has been shown to decrease pain, reduce healing time, and limit the spread of the infection.

DOSING: Acyclovir may be taken with or without food. Acyclovir is excreted mainly by the kidney and dosages need to be reduced in patients with kidney dysfunction.

DRUG INTERACTIONS: Genital herpes is a sexually transmitted disease and patients should avoid intercourse when they have visible lesions. Resistance to acyclovir can develop, especially with overuse. Therefore, acyclovir should be used only for severe cases and only as long as needed. Long-term suppression for recurrent genital herpes should include periodic re-evaluations and trials without the drug or intermittent short-term treatments.

SIDE EFFECTS: Rare side effects in patients treated short-term with acyclovir are nausea, vomiting, and headache. Long-term treatment has the additional potential for rash and diarrhea.

Caution! Before starting to take this medicine, it is vital that you should consult your doctor! Do not use it on your own initiative, without medical advice.