Pruritus in Elderly Patients

(Great Britain—The Practitioner, March 1999, p. 203.) Pruritus is common in older patients, with 29 to 50 percent of persons 75 years of age reporting chronic or recurrent skin irritation and itching. Localized pruritus in elderly patients usually involves the scalp, trunk, anal area, legs and feet, hands or inguinal areas. Generalized pruritus may be caused by skin conditions, especially xerosis, or a wide range of endocrine, hematologic, renal, hepatobiliary, neurologic, psychiatric, malignant or infectious conditions. Careful history and physical examination are crucial to making an accurate diagnosis. Evaluation may have to be repeated on several occasions because pruritus may precede other symptoms of a systemic illness by several years. Investigations and treatments should target the underlying cause of pruritus. The most common causes are senile pruritus and xerosis, both of which may be complicated by secondary infection. In addition to treatment of the underlying cause, pruritus should be treated with mild soaps and liberal use of emollients if the skin is dry. Antihistamines should be used with caution because of side effects but are useful for nocturnal sedation and relief. Histamine-induced itching may respond to doxepin in a low dosage. Urticaria and pruritus that are related to Hodgkin's disease may be relieved by histamine H₂ receptor-blocking drugs.

Nocturnal Enuresis

(Australia—Australian Family Physician, February 1999, p. 113.) Nocturnal enuresis often has multifactorial causes. In over 70 percent of cases, the circadian production of antidiuretic hormone (ADH) is abnormal, resulting in the production of large volumes of dilute urine at night. Nocturnal enuresis may also result from low bladder capacity, detrusor instability or poor sleep arousal, or it may be associated with other developmental, psychologic or physical conditions, including the use of medications. A strong family history is usually present; researchers have identified loci on chromosomes 12q and 13q that may play an important role in the etiology of some cases. Although a thorough history is essential, physical and laboratory examinations rarely provide additional diagnostic information. Treatment is recommended for children older than seven years with persistent nocturnal enuresis. Bed-wetting alarms, when used properly and persistently, provide success rates of over 70 percent. Families of children who use the alarms may require significant support. If alarms are unsuccessful after eight to 12 weeks, desmopressin may be successful. This synthetic analog of ADH is taken as a nasal spray, one puff in each nostril at bedtime. Desmopressin also works synergistically with alarms and is useful on occasions when the child has to sleep away from home and the alarm is impractical. Treatments such as imipramine and fluid restriction are no longer recommended.

Growing Pains

(Australia—Australian Family Physician, February 1999, p. 124.) Although “growing pains” are reported to occur in up to 20 percent of children, the topic continues to cause considerable controversy. A typical history is of a young child awakened by severe, symmetrical leg pain, frequently after a day of intense physical activity. Pain may also occur in the evening before bedtime. Parents are usually concerned that the pain may be caused by leukemia or cancer. Children with serious causes of limb pain (such as bone malignancy, osteomyelitis, leukemia and juvenile arthritis) usually have other physical findings, such as tenderness, swelling of joints, or hepatosplenomegaly and lymphadenopathy. Such children may also have disturbances of gait and appear unwell. If the child appears well and is clinically normal, serious pathology is unlikely, and further investigation is unnecessary. Addressing parental concerns, providing advice on symptomatic relief and ensuring follow-up are usually sufficient if there is no suspicion of serious pathology.

Tinea Versicolor

(Canada—Canadian Family Physician, March 1999, p. 618.) Tinea versicolor is an asymptomatic skin infection caused by the yeast Pityrosporum ovale. Lesions, which occur as scaly macules on the trunk, shoulders and arms, may coalesce into large patches and may be hypopigmented or hyperpigmented, depending on the production of phenolic compounds and the degree of hyperkeratosis. The diagnosis is usually based on clinical features, but potassium chloride preparation of scrapings shows characteristic hyphae and spores. Treatment with topical selenium preparations is usually effective; topical imidazoles are also useful. For widespread or resistant cases, oral azoles such as ketoconazole or triazoles (fluconazole or itraconazole) may be used.