dnobo

Flea Bites

This 26 year old health professional reported these extremely pruritic lesions after sleeping in a bed later found to be infested with fleas. Note the grouping; the elastic line for the patient's underwear and pants is at the level of the linear stripe of lesions on his side. The lesions are almost completely unilateral--there are only a couple of lesions on the left side and all covered areas were completely spared.

The pruritis resolved with loratadine and topical steroid therapy. Once the patient's bedding was changed and clothing washed he stopped getting new bites.

Varicella

This is the back of a 7 year old girl with varicella. Her brother had recently had the disease.

Amyopathic Dermatomyositis

Amyopathic dermatomyositis in a 24 year old female.

Dermatographism

These lesions developed shortly after the patient scratched her back and faded soon thereafter.

Primary Lyme Disease (Erythema Migrans)

The targetoid rash of erythema migrans found in a 48 year old male after a weekend in the woods. The patient was treated for lyme disease; no tick was ever spotted.

Koebner Phenomenon in Psoriasis

A linear stripe of psoriasis in a patient with a diffuse psoriasis flare after stopping methotrexate. The patient reports that this lesion formed after she was scratched on her leg by her cat.

Acrodermatitis Enteropathica

A classic presentation of acral dermatitis in a patient with acrodermatitis enteropathica.

Contact Dermatitis

A stripe of contact dermatitis caused by exposure to poison ivy. Note the linear shape left by brushing against the plant.

Herpes Zoster (Shingles)

A 27 year old male presented with three days of pain, erythema, and vesicles on the back of his right hand. He has no other medical history. A physical exam revealed the above lesions in addition to two small vesicles on the dorsal aspect of the arm in the same dermatome.