The history of the microscope reflects advances in science and medicine.

Microscopes, more than any other instrument, reflect advances in clinical medicine over the past several hundred years. As the primary tool of the pathologist, they were, and continue to be, a key connector between the bedside and basic sciences. One specific example is the science of clinical dermatology, which relies on clinical-pathologic correlation to make a definitive diagnosis. The microscopes used by pathologists, however, are more than scientific artifacts. Many antique microscopes are hand-crafted works of art. Even while recognizing that light microscopes may soon be obsolete as scanned slides and computer joy-sticks replace optical instruments in patient care and teaching, their significance will not be diminished. The microscope will never be forgotten in the history, art, and science of medicine, for these instruments set the social and cultural stage for modern, scientific patient care.

The CARE approach to reducing diagnostic errors.

BACKGROUND: Diagnostic errors appear to be the most common, costly, and dangerous of all medical mistakes. There has been a notable increase on the focus of error prevention as part of a growing patient safety movement. However, diagnostic errors have received less attention than other types of error. Our goal is to present a short mnemonic that can act as a checklist or posted reminder to help practitioners in dermatology or any field of medicine to avoid diagnostic errors. METHODS: To meet this goal, the authors reviewed the literature and discussed errors and potential errors they have experienced over 55 years of combined practice, to create a short mnemonic. RESULTS: The CARE method has helped the authors prepare and review their differential diagnoses in the relatively fast-paced practice of dermatology, but it has yet to be tested on a large scale. CONCLUSION: The CARE (communicate, assess for biased reasoning, reconsider differential diagnoses, enact a plan) method is an efficient, recallable checklist that uses an educational approach to reduce diagnostic error while reminding us to simply "care" from a humanistic perspective. This method may help reduce preventable diagnostic errors and improve patient care.

Pruritic, lightly-scaled patches on wrists.

A rash first appeared on this patient's left wrist and then spread to his right. Was his chrome-colored watch to blame--or was there a different cause?

The sarcoidal granuloma: A unifying hypothesis for an enigmatic response.

Although the cause of sarcoidosis is unknown, there is growing support for the concept that sarcoidal granulomas result from a hypersensitivity reaction producing a nonspecific response to an extrinsic or intrinsic (autoimmune) antigen in genetically susceptible individuals. The immune milieu associated with these antigens, localized in a specific cutaneous area, produces a variant of Ruocco's "immunocompromised district." This may explain the predilection for sarcoidal granulomas in association with foreign bodies, tattoos, herpes zoster-affected dermatomes, and scars. Similar antigenic stimulation produces sarcoidal granulomas surrounding internal tumors. Finally, systemic sarcoidosis, as manifested by hilar adenopathy, may reflect the lymphatic spread of foreign antigens.

Reducing cognitive errors in dermatology: can anything be done?

An increasing focus on the prevention of medical errors is a direct result of a growing patient safety movement. Although the reduction of technical errors has been the focus of most interventions, cognitive errors, usually more than one error linked together, actually cause the majority of misdiagnoses. This article examines the most common types of cognitive errors in dermatology. Two methods to minimize these errors are recommended: first, cognitive debiasing techniques reduce the common initiating factor of error cascades; and secondly, the application of prospective hindsight attacks the final common pathway that leads to misdiagnosis.

Case report: acanthosis nigricans resulting from repetitive same-site insulin injections.

Although acanthosis nigricans (AN) may be associated with internal malignancies, a benign form is more common, and a subset of these is drug-induced. In this case, a solitary, hyperpigmented, acanthotic plaque developed on the right abdomen after daily, same-site injections of insulin over a six-month period. The lesion completely resolved eight months after insulin injections were rotated to other locations. Acanthosis nigricans recurred, however, at the original location two months after the patient resumed serial same-site insulin injections, against medical advice. This provides direct evidence that localized hyperinsulinism is causally related to AN through its effect on insulin-like growth factor receptors.

Angular cheilitis, part 2: nutritional, systemic, and drug-related causes and treatment.

Angular cheilitis (AC) is associated with a variety of nutritional, systemic, and drug-related factors that may act exclusively or in combination with local factors. Establishing the underlying etiology of AC is required to appropriately focus treatment efforts.

Angular cheilitis, part 1: local etiologies.

Angular cheilitis (AC) is a common condition characterized by erythema, moist maceration, ulceration, and crusting at the corners of the mouth. This article focuses on the common local factors that act alone and in combination to produce AC. These factors are categorized as irritant, allergic, and infectious causes. Identifying the underlying etiology of AC is a critical step in developing an effective treatment plan for this condition.

Diphenhydramine as an alternative local anesthetic agent.

Patients who present with a history of "allergy" to local anesthetics are common in clinical practice. Injectable 1% diphenhydramine is a safe, inexpensive, and effective local anesthetic for simple dermatological procedures in patients who report "caine" allergies. Utilizing this agent permits the dermatologist to operate at the time of the initial visit and schedule a referral to the allergist for definitive sensitivity testing at the patient's convenience.