Cutaneous Emergencies

In examining a patient suspected of being infested with body lice:

Eggs and lice are usually limited to the patient's body and are unlikely to be found on clothing or possessions.

Egg casings are often found attached to the hairs of the arms and legs.

Lice infestation is a superficial problem and should not cause adenopathy or fevers.

Small pruritic erythematous spots on the skin are often found.

Furrows are pathognomonic.

Body lice and eggs are typically found on the inner surfaces of clothes in contact with the skin. The bites are small pruritic erythematous spots. Scratch marks may aid the diagnosis. Systemic reactions to lice feces and saliva, as well as pyogenic infections may lead to fever and regional lymphadenopathy. Egg casings are eccentrically located and firmly bound to terminal (thick) hair shafts. It is unusual to find lice on the fine (vellus) hair of the body. Furrows are characteristic of infestation by scabies mites.

A 23-year-old woman complains of dysuria and her urine is dipstick positive for leukocyte esterase. She also has symptoms of a mild upper respiratory infection, but is otherwise healthy and has no known allergies. You give her a prescription for ampicillin, but she returns 2 days later with a diffuse, nonpruritic rash over her abdomen and trunk. She is otherwise asymptomatic. You should now:

Advise her to continue the antibiotic because the rash does not itch.

Advise her to take diphenhydramine, 25 mg every 6 hours, and continue the ampicillin.

Inform her that ampicillin interacts with viral URIs, and to continue the ampicillin.

Discontinue the ampicillin and prescribe trimethoprim-sulfamethoxazole.

Discontinue the ampicillin and prescribe cefaclor.

Many drug eruptions can appear like viral exanthems. Ampicillin can cause skin rashes, particularly in patients with infectious mononucleosis. If a rash develops when taking a drug, the drug should be stopped and an appropriate alternative prescribed because continued administration can lead to erythroderma or exfoliative dermatitis. Although cefaclor is not contraindicated in this setting, it is expensive. Trimethoprim-sulfamethoxazole would be the best choice with the understanding that cutaneous reactions with this medication are not uncommon.

In patients with suspected Stevens-Johnson syndrome:

Oral lesions are common but rarely become secondarily infected.

Ocular involvement is exceedingly rare.

It often is complicated by thrombophlebitis.

Women may complain of vulvovaginitis.

Discomfort may be severe but fatalities are virtually unheard of.

The Stevens-Johnson syndrome is a severe form of erythema multiforme characterized by generalized bullae that involve the skin and mucous membranes, including the mouth, vagina, eyes, and esophagus. Dehydration results from painful stomatitis and weeping skin surfaces. Secondary infections of the denuded epithelium are common, as are severe ocular complications, including corneal ulcers and blindness. Thrombophlebitis is not particularly associated with the disease. Steroids provide symptomatic relief. The overall mortality is 5–10%.

A 4-year-old girl has had an exudative, encrusting skin eruption on her upper lip and both cheeks for more than a week. Her mother has applied a 0.5% hydrocortisone cream twice daily, but says the rash is getting worse. The most likely diagnosis and best treatment is:

Acne vulgaris → treat with tetracycline, 25 mg/kg every 6 hours for 7 days.

Impetigo contagiosa → treat with benzathine penicillin.

Bullous impetigo → treat with dicloxacillin, 50 mg/kg every 6 hours for 10 days.

Herpes zoster → treat with oral acyclovir and initiate immunodeficiency workup.

Nummular eczema → treat with warm compresses and a more potent topical steroid lotion, such as fluocinolone acetonide cream.

Acne does not occur in prepubescents, and tetracycline is contraindicated in children younger than 8 years. The two types of impetigo require different treatment. Impetigo contagiosa is caused by group A, beta-hemolytic Streptococcus and progresses from a small red papule to larger, honey-colored crusted lesions. Treatment should be the same as for a streptococcal infection of the throat, since some strains are nephrotoxic. Bullous impetigo is caused by phage group II staphylococci and the lesions appear as 0.5–3 cm pustular bullae without erythema. Presumptive treatment with oral antibiotics based on the clinical diagnosis is usually sufficient. Wound cleansing and topical antibiotics are also indicated in both types of impetigo. Eczema may become secondarily infected (“impetiginized”), and may be distinguished by the distribution of lesions and clinical history. Herpes zoster (shingles) is a vesicular eruption following a dermatomal pattern and does not cross the midline.

The most common manifestation of Lyme disease is:

Erythema migrans.

Meningitis.

Cognitive impairment.

Recurrent arthritis.

Heart block

Lyme disease is caused by the spirochete Borrelia burgdorferi. After B. burgdorferi is introduced into the skin, it spreads locally. The local spread leads to erythema migrans (EM), a rash that is found in approximately two-thirds of patients. Keep in mind that a rash may not be present in up to 20% of cases and even if present may be mild, nonspecific, and easily missed by the patient, family, caregivers, and/or the initial treating physicians.

In evaluating the skin lesions of patients with AIDS:

Kaposi sarcoma is common but seldom more than a cosmetic problem.

Candidiasis may occur but is easily treated with standard medications.

Tinea corporis is no more likely in these patients than in the general population.

Lichen planus of the oral mucosa is associated with the disease.

Seborrheic dermatitis-like eruptions are frequently found.

A virulent form of Kaposi sarcoma occurs in patients with AIDS. Recurrent, relatively refractory infections such as candidiasis and tinea corporis reflect the immunodeficiency state of AIDS. A seborrheic dermatitis-like eruption has been described in patients with AIDS and is characterized by abrupt onset of a symmetric, scaling erythematous rash primarily involving the face and chest. Lichen planus is a white lesion of the oral mucosa with no particular predominance in patients with AIDS (Tintinalli et al., 2003:932).

Two weeks ago, a 54-year-old man developed a cold sore, which resolved uneventfully. He now complains of a nonpruritic skin rash. Examination reveals raised red lesions resembling hives, some with clear fluid bullae. They are located on his hands, including the palms, and his forearms and anterior tibia. The best way to confirm your suspected diagnosis is by:

Viral culture of blister fluid.

Smear of blister fluid for Gram stain.

Tzanck preparation of blister fluid to look for multinucleate giant cells.

Full thickness skin biopsy of involved area.

Wood's light examination of involved areas.

Herpes simplex infection may precede erythema multiforme (EM). Affected patients may have recurrent bouts of the disease with each episode of herpes. The virus is not found in the blisters of EM, nor are fungi or bacteria. Immunofluorescent studies of a skin biopsy showing Ig-complement deposits at the dermoepidermal junction confirm the diagnosis. In mild cases, clinical diagnosis and outpatient treatment with topical steroids and close follow-up are sufficient. Other causes, such as drugs and malignancy, should be considered. Severe cases require hospitalization.

Scabies infestations usually spare the:

Intertriginous spaces of the hands and feet.

Areolar area in females.

Penile shaft in males.

Pubic area.

Scalp.

While scabies infestation may resemble lice infestation, the characteristic distribution of lesions aids in the differential diagnosis. Scabies bites are usually concentrated about the web spaces of the hands and feet. In adults, the nipple in females and the penis in males are frequent sites of involvement. Scabies rarely occurs above the neck in adults, who should be treated from the neck down with topical medications (permethrin, lindane, crotamiton, or in pregnant women, 5% sulfur ointment). Reapplication may be considered 1 week after initial treatment. The characteristic burrow of the female mite, a jagged white line with a gray dot at the end and overlying vesicles, is pathognomonic, but it is often obscured by the effects of scratching and may resemble dermatitis. Pruritus may persist after treatment and should not be interpreted as a treatment failure; antipruritic medications are indicated for symptomatic relief. Antibiotics may be indicated for secondary infections.

A mother brings her twin 5-year-olds, who are scratching at their feet and rubbing their hands. You note lightning-shaped red lines on the dorsum of their feet, but no signs of cellulitis. The mother tells you that her family physician diagnosed scabies and prescribed 1% lindane, which she used as directed 4 days ago. She is insistent that the treatment must have failed and something more be done. Her physician is out of town. You should:

Prescribe lindane to be applied when necessary for 1 week.

Prescribe lindane to be applied one additional time from the neck down in each child.

Prescribe lindane to be applied to the scalp and below the neck one additional time, since reinfestation from the scalp is common.

Reassure the mother, have her trim her children's nails, and prescribe calamine lotion and acetaminophen with codeine elixir as needed.

Prescribe erythromycin, 200 mg every 6 hours for at least 7 days, and topical calamine lotion for itching.

The lesions and itching of scabies often persist after successful treatment. Reapplication of scabicidal medications should not be considered until 1 week after initial treatment. Antipruritic agents and analgesics should be used as needed in the interim for relief. Lindane (gamma benzene hexachloride) is absorbed through intact skin, and neurotoxicity with seizures has been reported after its use. The drug itself can also result in a dermatitis. Alternative scabicidal agents (5% sulfur ointment) should be used in children and pregnant women. Antibiotics are used only if secondary infection is present.

An avid 65-year-old male golfer presents with a 1-week history of a progressive eczematous skin rash. It is diffuse, symmetrical and involves the face, ears, and left forearm. He wears a golf glove on his right hand. Past medical history is positive for hypertension, which is controlled by a “water pill.” Based on this information, he probably has:

Toxic epidermal necrolysis.

Erythema nodosum.

Erythema multiforme.

Fixed drug eruption.

Photoallergic dermatitis.

Photoallergic dermatitis is an eczematous skin rash involving the sun-exposed surfaces of the body and may occur with the use of many drugs. This patient's right forearm was spared because of his use of a golf glove. Toxic epidermal necrolysis is a generalized blistering disease that involves the mucous membranes. Erythema nodosum has multiple, bilateral, tender nodules that occur on the lower legs. Erythema multiforme is a disease of evolving skin lesions, which begin as nonpruritic plaques that develop dusky centers (“target lesions”). Fixed drug eruptions are idiosyncratic reactions, typically a single, 2–3 cm, red lesion that develops in the same site every time the drug (tetracycline, barbiturates) is ingested.

Choose the true statement concerning toxicodendron dermatitis:

Systemic corticosteroids are rarely effective in the treatment of poison ivy.

In severe bullous toxicodendron dermatitis, care must be taken to avoid spreading the eruption by contact with allergens in the blister fluid.

Patients sensitive to poison ivy react to poison oak but not poison sumac.

The allergen of toxicodendron dermatitis is rapidly destroyed by alcohol, resulting in an inactive product called urushiol.

The allergen of toxicodendron dermatitis is rapidly inactivated by household soap and water.

The characteristic rash of poison ivy develops 24–72 hours following exposure. Systemic corticosteroids are used to treat moderate-to-severe cases. Prednisone, 40–60 mg/day tapered over 2–3 weeks, should be prescribed; shorter treatment may result in a rebound dermatitis. Blister fluid is a plasma derivative, does not contain the active allergen and cannot spread the dermatitis. Urushiol is the allergen-containing plant resin and cannot be inactivated by alcohol. The allergens of the three plants (poison ivy, poison oak, and poison sumac) cross-react immunologically; an individual sensitive to one is sensitive to all. Soap and water rapidly inactivate the allergen.

The most important initial therapy for a patient with toxic epidermal necrolysis (TEN) is:

Corticosteroids.

Antibiotics.

Anticoagulants.

Analgesics.

Crystalloids.

Hydration is the single most important intervention. A patient with TEN is in acute skin failure. Because the most important function of the skin is to store water, loss of this barrier results in possible dehydration. Dehydration can result in acute renal failure and subsequent shock. Even with aggressive treatment; however, morbidity and mortality are high with this condition.

A 45-year-old man presents with a nontender, 0.5 cm erosion at the base of the anterior aspect of the glans penis. After gently abrading the lesion, a sample is collected and immediate dark-field examination reveals spirochetes. Your next step is to:

Obtain a culture of the lesion and treat with procaine penicillin 4.8 million units IM, half in each buttock.

Treat empirically with 4.8 million units of benzathine penicillin IM, report the case to the health department, and inform the patient he needs to notify his sexual partners.

Treat empirically with 2.4 million units benzathine penicillin IM, obtain tests for VDRL and HIV antibody, and initiate case–control follow-up.

Treat empirically with 4.8 million units procaine penicillin plus probenecid, 1 g po, and prescribe doxycycline 100 mg po bid for 10–14 days; initiate case–control follow-up and obtain urethral culture and serum VDRL.

Treat empirically with 4.8 million units procaine penicillin plus probenecid, 1 g po, and prescribe doxycycline 100 mg po bid for 7 days; initiate case–control follow-up, obtain urethral, rectal, and oropharyngeal cultures, plus VDRL and FTA-ABS tests.

This patient has primary syphilis. Adequate treatment is provided by choice c; however, since there is a high incidence of coexisting sexually transmitted diseases, many physicians might empirically treat with a regimen effective against gonorrhea and chlamydia. A baseline quantitative VDRL should be obtained. Whether to test for HIV antibody is controversial, but the patient should be questioned about risk factors. A urethral swab for gonorrhea would be appropriate, but in the absence of any suggestive findings rectal and pharyngeal cultures would not. Most states require notification of the health department of positive results. The patient should be counseled to notify his sexual partners. Follow-up is required to confirm successful treatment.

The condition that characteristically results in recurrent axillary and groin abscesses is:

Regional enteritis.

Diabetes mellitus.

Ulcerative colitis.

Hidradenitis suppurativa.

Acne conglobata.

Hidradenitis suppurativa is characterized by recurrent infections of the apocrine glands. These glands are located in the axillary, anal, groin, and mammary areas. Carbuncles on the back of the neck and perianal abscesses are typical sites of infection in diabetic patients. Regional enteritis may lead to perianal fistulas, abscess formation; however, it would not involve the axilla. Ulcerative colitis is associated with pyoderma gangrenosum and erythema nodosum. Acne conglobata is a severe form of acne vulgaris and primarily involves sebaceous glands of the face and back.

A 22-year-old man is concerned about patches of skin on his arms and shoulders that do not tan like the surrounding skin. A likely diagnosis is:

Tinea versicolor.

Vitiligo.

Pityriasis.

Acne vulgaris.

Piebald albinism.

Tinea versicolor, a yeast infection resulting in patches on the chest and trunk and occasionally the head and extremities. The lesions have a fine scaly appearance and appear hypopigmented.

A 20-year-old man complains of a rash on his back for 1 week. It is mildly pruritic. You note numerous oval, 1.5 cm slightly scaly lesions. One lesion on his left flank measures 3.5 cm and occurred several days before the other lesions. You recommend:

Oral antifungal therapy.

Topical steroids.

High-dose IM penicillin for the patient and all sexual contacts.

Patience and antipruritics; the problem is self-limited.

Hepatic function panel.

Pityriasis rosea is a mild, self-limited skin eruption whose cause is unknown. It occurs primarily in children and young adults. Oval lesions occur in a Christmas tree-like pattern on the trunk. A larger “Herald patch” precedes the eruption in roughly half the cases. It resolves spontaneously in 2–3 months.

Erythema nodosum may occur in patients with tuberculosis, sarcoid, ulcerative colitis, histoplasmosis, coccidiomycosis, or infections with Streptococcus, Chlamydia, and Yersinia enterocolitica. It can also be drug related, with the most common culprit being:

Penicillin.

Sulfa drugs.

Oral contraceptives.

Cephalosporins.

Erythromycin.

Oral contraceptives are the medications most commonly associated with erythema nodosum. Pregnancy has also been noted to have an association with erythema nodosum.