Ted Rosen, MD

A 16-year-old girl presented with an extremely pruritic rash on the ventral aspect of both arms. She was in good health, had never suffered from eczema, and took no medications. 



 The symmetry and limited distribution of the eruption suggests that it may be caused by something that comes in contact with the inside of the arms. Lesional morphology and distribution is characteristic of ectoparasite bites, which occur when a human carries a pet-usually a kitten or puppy-as if the animal were a human newborn baby. On direct questioning, the patient noted the acquisition of a new kitten in the last few weeks. The most common ectoparasite responsible for this type of eruption is the mite, cheyletiella.



 The animal should be examined to confirm infestation and then professionally treated by a veterinarian to preclude ongoing problems. Old bites spontaneously resolve.



 Always inquire about exposure to animals when you encounter an unusual rash.

Articles

The morphology and distribution of these lesions is characteristic of ectoparasite bites, which occur when a human carries a pet-usually a kitten or puppy-as if the animal were a human newborn baby.

Ectoparasite Bites from a Kitten

A young man sought medical attention after a motorcycle mishap that led to multiple leg abrasions. One such lesion expanded rapidly and became progressively painful. The patient was alarmed when the center of the lesion turned dark. 

 The black, hard center represents an eschar. This type of morphology is almost always caused by a virulent organism-bacterial or fungal. Because of the outdoor, traumatic onset, a fungal etiology was suspected. A biopsy showed non-septate hyphae within the dermis, and a culture grew 

 Wide surgical debridement and intravenous administration of liposomal amphotericin-B were required to stop the spread of the destructive lesion and thereby save the leg. 

 Similar cases have occurred, in both adults and children, following significant automobile accidents.

The black, hard center represents an eschar. This type of morphology is almost always caused by a virulent organism-bacterial or fungal. Biopsy showed non-septate hyphae within the dermis, and a culture grew Mucor species (a saprophytic soil fungus).

Life-Threatening Fungal Infection Following a Motorcycle Accident

Not all patients with life-threatening dermatologic disorders are sick enough or symptomatic enough to go to the emergency department . . . some may come to your office with what may look like a relatively benign lump or bump. Yet within a few hours, such lesions can cause significant morbidity or even death.

In a series of photo-rich short videos, Ted Rosen, MD, Professor of Dermatology at Baylor College of Medicine and Chief of the Dermatology Service at the VA Center in Houston, focuses in on common and not-so-common dermatologic emergencies. In each segment, he offers practical guidance on early recognition and appropriate intervention measures.

In this first segment, Dr Rosen offers 4 basic ground rules.

1. The severity of visible pathology does not always correlate with degree of severity of disease process (think gonococcemia, which may present with just a few small hemorrhagic lesions).

2. Given 2 conditions of a similar severity, you may need some ancillary information to decide what is or is not important.

3. Given 2 life-threatening disorders, the true need for rapid intervention may vary greatly.

4. You don’t always need to know the right diagnosis immediately. The key is to distinguish between a life-threatening or emergent situation versus something that is urgent and important versus something that is commonplace.

Not all patients with life-threatening dermatologic disorders are sick enough or symptomatic enough to go to the emergency department. . .  some may come to your office with what may look like a relatively benign lump or bump. Yet within a few hours, such lesions can cause significant morbidity or even death.

Life-Threatening Dermatologic Disorders in Infants and Children: Part 1

A 17-year-old man, who was being treated for Hodgkin lymphoma, presented for medical attention because of the presence of extremely painful “sores” on his lip. He also had newly developed palpable submandibular and submental lymphadenopathy. 



 The multiple shallow to deep erosions on the lower lip began, by history, as blisters. There is still a solitary, intact vesicle still visible (arrow). The eruption is most likely an exaggerated version of herpes labialis relating to the patient’s underlying lymphoma. A viral culture would be useful just to verify the diagnosis, and an intact vesicle facilitates this. 



 Appropriate oral doses of acyclovir, valacyclovir, or famciclovir should be administered, and topical anesthetic given to prevent dehydration from lack of fluid intake relating to labial pain.    



 Lymphadenopathy is likely caused by herpetic infection, but should it persist after the lip lesions resolve, a biopsy may be in order.

The multiple erosions on this teenager's lip are most likely an exaggerated version of herpes labialis related to his underlying lymphoma. A viral culture would be useful to verify the diagnosis.

Author | Ted Rosen, MD

Articles

Ectoparasite Bites from a Kitten

Life-Threatening Fungal Infection Following a Motorcycle Accident

Life-Threatening Dermatologic Disorders in Infants and Children: Part 1

Herpes Labialis in an Immunocompromised Patient