Dermatology

This is a classic keratoderma, which can be due to a variety of congenital defects in keratinization or acquired in association with disease states. Retinoids, systemic and topical, are the treatments of choice.

This solitary, very pruritic, annular lesion suggests dermatophytosis. KOH preparation verified the presence of Tinea faciei. This infection is usually associated with contact with a new kitten or puppy.

This clustered grouping of small, shallow erosions surmounting a slightly indurated plaque is characteristic for “cold sores.” Because no vesicles were present and the lesions appeared to be crusting over, the patient was advised to apply an OTC cream (docosanol 10%) per package insert instructions.

These small, pruritic papules appeared in the morning, which strongly suggests the bite of a nocturnal feeding arthropod. Insect bites arranged in clusters of 3 is typical for, but not diagnostic of, bedbug infestation.

This green discoloration is the result of subungual Pseudomonas aeruginosa colonization. Pathogenic bacteria can enter this space via many causes, including trauma or underlying lesions.

Guttate psoriasis often appears in conjunction with an upper respiratory infection, particularly streptococcal tonsillitis, as it did in this patient. This phenomenon is more common in children.

These oval, dyschromic macules surrounded by a palpable scale-like border are pathognomonic of disseminated superficial actinic porokeratosis, a disorder seen usually in those who have had considerable lifelong exposure to sunlight.

Prominent, pigmented polyangular scales on the extensor surfaces of the arms, legs, and trunk suggested recessive X-linked ichthyosis. DNA analysis demonstrated an abnormal steroid sulfatase gene, which confirmed the diagnosis.

Eccentric darker pigmentation in this small asymptomatic lesion strongly suggests malignant melanoma. This patient had a history of non-melanoma skin cancer, but was unaware of the questionable growth.

This is a classic keloidal mass, which can occur in any ethic group. Because keloids can be intensely painful, they almost always require removal.

Histopathology showed this neoplasm to be a seborrheic keratosis: it might well have been a hypertrophic actinic keratosis, melanoma, or superficial basal or squamous cell carcinoma.

This patient wonders whether the insect he found on his headboard might be responsible for the clusters of pruritic, crusted papules on his legs. This turned out to be a bed bug.

The areas that contained linear erythema, punctuated by stippled pigmentation, and a small round area of stippled pigmentation were biopsied: both showed pigmented basal cell carcinoma.

This new-onset “growth” was removed and shown to be a solitary neurofibroma, which is not an indication of any of the genodermatoses marked by a multiplicity of such neoplasms.

Biopsy of the 3 red “spots” in close proximity showed lichenoid keratosis-a benign lesion, probably related to seborrheic keratosis, which often mimics skin cancer.

While it might be tempting to dismiss this as a picker's nodule, lesion's thickness suggested the need for a biopsy, which revealed that the lesion was an infiltrative, invasive basal cell carcinoma. The lesson? Never hesitate to biopsy when the slightest uncertainty exists as to the correct diagnosis.

The predominantly infraorbital erythema and swelling suggested that this rash was related to a material that was being placed in the eyes and dripping from them. Patch testing showed that the patient was allergic to the preservative in the eyedrops she had been using.

The translucent papule on the upper lip has a few small blood vessels that traverse its surface. These are morphologic features of basal cell carcinoma, a presumptive diagnosis that was confirmed by biopsy.

The redness on this woman's nose represents fairly severe photodamage with extensive actinic keratosis. Use of a topical therapy to achieve clearance of a field of actinic damage can be done with imiquimod, 5-fluorouracil, or ingenol mebutate creams, or diclofenac gel.

Cutaneous horns can arise on top of: seborrheic keratosis (as in this patient’s case), actinic keratoses, warts, basal and squamous cell carcinomas. Therefore, the lesion-and especially the base-must be submitted for pathologic diagnosis.

“Stippled” pigment is highly typical of a pigmented basal cell carcinoma. Diagnostic contenders include atypical seborrheic keratosis and superficial spreading melanoma.

The morphology of a round, red to purple patch, with or without blistering, is typical of a fixed drug eruption. This entity usually manifests as a solitary spot, but can be multiple. Tetracycline antibiotics and barbiturate sedatives are common causes. This patient had been taking doxycycline.

This friable lesion with rapid and destructive growth is classic for granuloma inguinale. This patient was treated successfully with trimethoprim/sulfamethoxazole.

Condylomata acuminata this extensive are beyond the capacity of all topical therapies. The area was initially treated by carbon dioxide laser ablation, and residual small foci of infection were subsequently treated with topical 5% imiquimod cream.

The combination of itching massive scaling suggests the diagnosis of crusted scabies. This variety of scabies is seen in those who are immunosuppressed or immunocompromised (typically HIV+). Repeated oral doses of ivermectin along with topical permethrin application were required to clear this infestation.

A 24-year-old woman sought medical attention because of the acute onset of a very painful vulvar rash. She had never experienced anything similar. Do you recognize these lesions?

The patient received standard acyclovir dosage for first outbreak genital herpes: 200 mg orally, 5 times daily, for 10 days total. At this point, there is no way to predict how often or how severe future recurrences will be.

This painless, indurated ulcer is typical of the chancre of primary syphilis. This patient also had a positive RPR in a titer of 1:32.

Any adult with patchy hair loss with preservation of follicular openings should be questioned about sexual exposures. This presentation is not typical of alopecia areata, and the patient is too old for tinea capitis to be a major consideration.

Chlamydia trachomatis, serovar L2b-a recently discovered microbe-was the cause of atypical lymphogranuloma venereum in this HIV-positive patient.