Dermatology

This darkly pigmented lesion on the left arm of a 27-year-old man had been present since birth and had slowly enlarged over the past 2 months. Two days earlier, another physician had diagnosed a wart and treated the lesion with liquid nitrogen, which caused erythema of the surrounding skin.

I'm sure our office has many rulers, but I often do not have one readily available during a skin examination. When this happens, I have found that knowing the width of the nail on my index finger comes in handy.

Tinea is caused by dermatophytes that can infect the stratum corneum epidermidis, hair, and nails. Dermatophytosis is a common infection worldwide, and about 20% of the US population is infected.1 Although numerous fungi can cause tinea, Trichophyton, Microsporum, and Epidermophyton are the genera that cause most cases of tinea.2 Classified by the part of the anatomy that is infected, tinea is referred to as tinea pedis, tinea manuum, tinea cruris, tinea corporis, tinea capitis, tinea faciei, tinea barbae, and tinea unguium.

For several years, a 71-year-old man has had a mildly pruritic rash on his legs that develops every winter and resolves when the weather becomes warmer. He is scheduled to undergo knee surgery, but the surgeon refuses to perform the operation until the rash has cleared.

Half way through a 15-minute iontophoresis treatment for de Quervain tenosynovitis of the right wrist, a 42-year-old woman felt exquisite pain but completed the session. After the therapist returned to the room and removed the electrodes, a light gray circular mark about 5 mm in diameter was noted on the skin. The epidermis was gone, and the underlying dermis was also injured. Within 6 hours, a tender, dark red-brown lesion developed.

Black discoloration appeared on the fingernails of a 51-year-old white man who had sustained burns on 15% of his body in a house fire 2 months earlier. The discoloration is a typical side effect of silver nitrate, which was applied to his skin and fingernails during the month he was hospitalized. This topical broad-spectrum bacteriostatic agent is used to reduce the risk of infection and mortality in burn patients.

A Photo Quiz to Hone Dermatologic Skills

For 3 years, my 30-year-old patient has had outbreaks of small, vesicular, frequently pruritic lesions on the neck and upper trunk.

Blood under the nail can be easily removed-and the pain almost completely relieved-by timely nail trephination. Here: techniques that have worked well in my practice.

Dermclinic

Transverse depressions like the one shown here appeared on all the other nails of this 68-year-old man several weeks after he had suffered a myocardial infarction.

For 3 months, a 24-year-old man-a military aviator-had a worsening rash on his chest. He had no lesions elsewhere. Culture of the ulcers grew Pseudomonas. A 2-week course of antibiotic therapy was ineffective.

Younger patients are sometimes reluctant to have you use a liquid nitrogen spray gun to freeze their warts, because it can be painful.

Dermclinic

A 48-year-old Hispanic man had a tender, bleeding growth within a darkly pigmented plaque on the right flank. The pigmented lesion had been present since birth; it was previously asymptomatic. The tumor arose out of the mainly flat patch 6 months earlier and had slowly enlarged. The patient worked indoors, wore sunscreen daily, and generally avoided outdoor activities. He had no family history of skin cancer.

A 44-year-old man presented to the emergency department (ED) with pain and swelling of the left ankle and a petechial rash in the pretibial area that developed the night before. He also reported "fluttering" in his chest.

A 75-year-old man is concerned about the discoloration of his fingernails: each nail has dark bands with a clearing in the middle.

A 37-year-old man presents with moderately pruritic urticarial papules on areas of his skin that are not covered by his shorts and T-shirt. He recently returned from a trip to Upstate New York, where he had stayed in several rustic cabins that were used by different people daily.

When patients are allergic to adhesive tape, use transparent cellophane tape instead. They usually are not sensitive to it.

A Photo Quiz to Hone Dermatologic Skills

The red, 1- to 3-mm lesions on the right forearm of a 19-year-old man had recently become tender after being asymptomatic for 10 years. The patient described a shooting pain on palpation. Previous biopsy results showed no cancer. He had high blood pressure but was otherwise healthy. His father had similar lesions.

For 2 weeks, a 43-year-old white female had worsening nausea and multiple episodes of vomiting. Her symptoms began with increased malaise and decreased appetite. The emesis was unrelated to meals and was sometimes accompanied by mild abdominal distention. She had occasional fevers but denied any recent contact with ill persons. She also reported a 12-lb weight loss, decreased energy level, and an increased tan complexion over the past several months.

A 66-year-old woman was hospitalized because of severe anemia secondary to myelodysplastic syndrome. She had had associated fatigue and throbbing pain in both legs for several days.

For 2 weeks, a previously healthy 40-year-old man has had excessive thirst and increased frequency of urination. He awakens at least 5 times every night to urinate. He reports no nausea, vomiting, change in bowel habits, chest pain, or dyspnea.

A 20-year-old white male collegiate basketball player has a 3-year history of marked facial and upper extremity flushing that occurs after about 20 minutes of indoor practice. The flushing is preceded by an intense sensation of coldness, and despite the very noticeable flushing, the involved areas are cold to the touch for some time.

Worsening painful ulcers on both legs prompted a 62-year-old woman to seek medical attention. She had a history of rheumatoid arthritis (RA), demonstrated by the markedly deformed interphalangeal joints in her thumbs (A), and scleroderma-polymyositis overlap syndrome.

A 74-year-old woman presented with a refractory pruritic eruption. Four months earlier, she had sought evaluation of a thickened, slightly crusted 6 3 8-cm patch on her right ankle of 2 months' duration. Contact dermatitis with secondary impetigo from scratching was suspected, and a topical corticosteroid and an oral antibiotic were prescribed.

A painful necrotic lesion, a pruritic rash that recurs after corticosteroid therapy, an ulcer on the tongue-do you recognize the disorders pictured here?

Six months after testing positive for HIV in 10 bands, a 24-year-old homosexual man presented with a macular rash on his palms and soles. He first noticed the lesions 2 weeks earlier; they were not pruritic or painful. He also had a brighter, more inflamed rash in the groin and antecubital fossae that was presumed to be a yeast infection and was treated with fluconazole. He had no other symptoms.

The sharply demarcated, smooth red plaques on this 3-year-old's tongue had been present for several months.