A blue-black nodule has been present next to a 19-year-old woman’s left eyesince birth. After recent accidental trauma, the lesion has enlarged.
A blue-black nodule has been present next to a 19-year-old woman's left eyesince birth. After recent accidental trauma, the lesion has enlarged.
What does this look like to you?
A. Nevus of Ota.
B. Cellular blue nevus.
C. Combined nevus.
D. Spitz nevus.
Which of the following statements is true of this lesion?F. It appears more commonly on a buttock.
G. It is more common in women.
H. It most commonly appears at birth or at about age 40 years.
I. It can invade the skull.
J. It is associated with endocrine overactivity.
Bonus question: Why does this pigmented lesion appear grayish blue-blackrather than brown or black?
The biopsy confirmed a benign
cellular blue nevus,
These nevi are evenly colored gray, bluish, or black andhave symmetric, smooth borders. Congenital or acquired,single or multiple blue nevi can arise at any location. Statements
F, G, H,
characterize these lesions. Althoughthey are benign, these congenital lesions occasionally canbe invasive. Increased endocrine activity is not associatedwith these nevi.A nevus of Ota is a gray or bluish macule that involvesthe eye. Combined nevi generally possess features of bluenevi and of compound nevi, with one of the lesions layeredatop the other. These usually thicker nevi are typically darkerbrown to black, symmetric, and have smooth borders;they can be found anywhere on the body. Spitz nevi usuallyare pink, brownish red, or purplish red lesions of less than10 mm. Melanoma is always a concern; this patient's nevusresembled a nodular variant of skin cancer. The biopsyruled out a malignancy.Answer to the bonus question: The grayish blue-black color is attributed to bending light rays; dermal melanin fromdermal melanocytes is brown on the surface of the skin but appears to be gray or blue when below the surface.
An 11-year-old boy has had "itchybumps" on the sides of his fingers for1 week. The vesicles arose after thepatient had been on a roller coaster.
Which of the following do yoususpect?
B. Tinea manuum.
D. Contact dermatitis.
Bonus question:Which are potentialaggravating factors for this patient'sdisorder?A. Tinea pedis.
B. Nickel allergy.
C. Female sex.
D. Atopic dermatitis.
A--which meansbubble and is also known as dyshidrosis--is characterized by pruritic vesicleson the sides of the fingers andhands. Stress induced by fear of theroller coaster ride is thought to haveprecipitated this patient's disorder.
It is more common for a contactdermatitis to erupt on exposedareas--rather than the sides--of thefingers. Scabies is intensely pruriticand more widespread than the eruptionin this patient, and it features fewintact vesicles. Tinea manuum--adermatophyte infection of the hand--generally develops more slowly thanthis patient's rash and is more scalythan vesicular.Answer to the bonus question: In addition to stress, tinea pedis,
are aggravating factors for pompholyx. Atopy may be a risk factor,although the relationship has not been firmly established. Neither hyperhidrosisnor the patient's gender is associated with the disease.
An asymptomatic, circular, scaling lesion on the trunk of a 42-year-old man consistentlyreappears after clearing. The lesion initially erupted 3 months earlier;since then, it has arisen, lasted a few weeks, and disappeared several times. Thepatient has no other complaints; he takes no medications.
Your differential includes . . .
A. Tinea corporis.
B. Tinea versicolor.
C. Granuloma annulare.
D. Erythema annulare centrifugum.
E. Lupus erythematosus.
What do you include in your initial workup?
F. A bacterial culture.
G. A test for antinuclear antibodies.
H. A potassium hydroxide examination.
I. Measurement of fasting plasma glucose levels.
The presentation strongly suggested
erythema annulare centrifugum,
a reactive process to an underlyingdisease that is often undiagnosed. Tineacorporis, tinea versicolor, and granulomaannulare lesions do not wax andwane as did this patient's eruption. Therash of lupus erythematosus also tendsto persist and typically arises on sunexposedskin.Perform a potassium hydroxideexamination,
for a dermatophyteinfection, which is the most commonunderlying disorder; this patient hadtinea pedis. Further workup is neededonly if the patient has symptomsother than the rash. Treatment of thetinea pedis resulted in resolution ofthe infection and the erythema annularecentrifugum as well.
A persistent, pruritic plaque on one shin has bothered a 75-year-old man for 5years. Over-the-counter preparations have not resolved the lesion.
Do you recognize this eruption?
A. Stasis dermatitis.
B. A dermatophyte infection.
C. Impetigo with cellulitis.
D.A Candida infection.
E. Lichen simplex chronicus.
You prescribe which of the following?
F. A corticosteroid cream.
G. An antifungal cream.
H. An oral antibacterial agent.
I. An oral antifungal agent.
J. Occlusive dressings.
This excoriated plaque is
lichen simplex chronicus
which is often referredto as "the itch that rashes." This self-inflicted dermatosis is frequentlytriggered by a precipitating factor. To confirm the diagnosis, occlude the lesionso that the patient has no access to the area and examine it 1 or 2 weeks later.Invariably, significant healing will have occurred because the lesion was notrubbed or scratched.Occasionally, particularly in patients with long-standing disease, it is notpossible to identify the inciting cause of the chronic itch/scratch cycle. However,it is reasonable to search for underlying chronic disease, such as venousinsufficiency, myxedema, or xerosis. Tailor treatment to the inciting disorder.This patient had long-standing xerosis; a corticosteroid cream,
ameliorated the pruritic skin condition.