Update and future of systemic acne treatment.

Systemic treatment is required in patients with moderate-to-severe acne, especially when acne scars start to occur. antibiotics with anti-inflammatory properties, such as tetracyclines (oxytetracycline, tetracycline chloride, doxycycline, Minocycline and limecycline) and macrolide antibiotics (erythromycin and azithromycin) are the agents of choice for papulopustular acne, even though the emerging resistant bacterial strains are minimizing their effect, especially regarding erythromycin. Systemic antibiotics should be administered during a period of 8-12 weeks. In severe papulopustular and in nodulocystic/conglobate acne, oral isotretinoin is the treatment of choice. Hormonal treatment represents an alternative regimen in female acne, whereas it is mandatory in resistant, severe pubertal or post-adolescent forms of the disease. Compounds with anti-androgenic properties include estrogens combined with progestins, such as ethinyl estradiol with cyproterone acetate, chlormadinone acetate, desogestrel, drospirenone, levonogestrel, norethindrone acetate, norgestimate, and other anti-androgens directly blocking the androgen receptor (flutamide) or inhibiting androgen activity at various levels, corticosteroids, spironolactone, cimetidine, and ketoconazole. After 3 months of treatment control of seborrhea and acne can be obtained. Low-dose corticosteroids (prednisone, prednisolone, or dexamethasone) are indicated in patients with adrenal hyperandrogenism or acne fulminans. New developments and future trends represent low-dose long-term isotretinoin regimens, new isotretinoin formulations (micronized isotretinoin), isotretinoin metabolites, combination treatments to reduce toxicity, insulin-sensitizing agents, 5alpha-reductase type 1 inhibitors, antisense oligonucleotide molecules, and, especially, new anti-inflammatory agents, such as lipoxygenase inhibitors. Copyright 2003 S. Karger AG, Basel

Feline chlamydiosis.

Chlamydiae are an important cause of acute and chronic conjunctivitis in cats. Until recently, only one organism was thought to infect cats, Chlamydophila felis (previously Chlamydia psittaci var. felis). Recently, other Chlamydia-like organisms belonging to the family Parachlamydiaceae, which comprises organisms that reside and proliferate within free-living amoeba, have been identified in cats with neutrophilic and eosinophilic conjunctivitis. The relative importance of these organisms and their amoebic hosts requires investigation. There is also weak evidence that chlamydiae may also be capable of causing reproductive tract disease and lameness in cats. Diagnosis of chlamydial conjunctivitis requires use of specialized culture techniques or the polymerase chain reaction. The antibiotic of choice to treat these infections is doxycycline; azithromycin is less effective. All cats in the household should be treated simultaneously. The zoonotic potential of these organisms appears low, but some precaution is warranted when handling affected cats.

Systemic medications: clinical significance in periodontics.

Systemic medications are of value as adjuncts to periodontal therapy. These medications can be divided into two major categories: antibiotics and agents for host modulation. antibiotics have been shown to be valuable adjuncts in specialized types of periodontal disease, such as localized and generalized aggressive periodontitis, and of possible value in severe chronic periodontitis. antibiotics have been studied individually, in combination and in sequential therapy. Host modulators include Periostat, non-steroidal anti-inflammatory agents, alendronate (Fosamax), hormone replacement therapy and anti-arthritic medications. These agents produce their beneficial effects by a variety of mechanisms of action, including inhibition of matrix metalloproteinases, inhibition of prostaglandin production, stimulation of osteoblasts, inhibition of osteoclasts, and other anti-inflammatory mechanisms of action.

Subantimicrobial dose doxycycline (Doryx)for acne and rosacea.

Acne vulgaris and rosacea present therapeutic challenges due to their chronicity, potential for disfigurement, and psychosocial impact. Although pathophysiologically distinct, both conditions have major inflammatory components. Consequently, topical and systemic antimicrobial agents are routinely prescribed for extended periods. Emergence of resistant strains of Propionibacterium acnes, adverse events, and compliance issues associated with chronic systemic tetracycline use have led to new treatment approaches. At subantimicrobial doses, tetracyclines reduce inflammation via anticollagenolytic, antimatrix-degrading metalloproteinase, and cytokine down-regulating properties. Subantimicrobial dose (SD) doxycycline (Doryx)(Periostat 20 mg) has clinical utility in periodontitis and has been investigated in a double-blind, placebo-controlled trial in the treatment of moderate facial acne as well as in an open label study in the treatment of rosacea. The results of subantimicrobial dose doxycycline (Doryx)treatment in early trials support its benefits and further investigation in acne and rosacea.