Chapter 69 Dermatologic trivia
1. What does the X in histiocytosis X mean?
It expresses the common etiologic link among the three clinical forms of the disease: eosinophilic granuloma, Hand-Schüller-Christian disease, and Letterer-Siwe disease. When Louis Lichtenstein coined the name histiocytosis X in 1953, he chose the X to represent the then-undetermined cause of the disorders. He wrote that the suffix X “has the advantage of brevity and, by implication, emphasizes the necessity for an intensive search for the etiologic agent.” We now know that the common link is a proliferation of dendritic cells that are ultrastructurally and immunologically similar to Langerhans cells. Indeed, they probably are Langerhans cells, as reflected in the current name for histiocytosis X—Langerhans cell histiocytosis. Much about the disorder is still unknown, so perhaps Langerhans cell histiocytosis deserves to keep an X-designation.
Lichtenstein L: Histiocytosis X, Arch Pathol 56:84–102, 1953.
4. Several names are used for the disease caused by Bartonella bacilliformis: bartonellosis, verruga peruana, Peruvian warts, Oroya fever, and Carrión’s disease. Who was Carrión?
Daniel Carrión studied the relationship between the disfiguring, but seemingly benign, cutaneous disease verruga peruana, and the often-deadly disease Oroya fever. As part of a student research competition in 1885, the 26-year-old medical student inoculated himself with the blood of a patient with verruga peruana. Carrión soon developed the malignant form of Bartonella infection, Oroya fever, characterized by high fevers, severe myalgias, and profound hemolytic anemia. He postulated that the two conditions were related, but his experiment sadly ended fatally. A few decades later, his theory was proven correct, and now Carrión is the hero of the Peruvian medical profession.
Leonard J: Daniel Carrión and Carrión’s disease, Bull Pan Am Health Organ 25:258–266, 1991.
5. What other illnesses are caused by Bartonella species?
Cat-scratch disease is caused by B. henselae, and trench fever is caused by B. quintana. Other conditions caused by various Bartonella species (including B. henselae and B. quintana) are most common in immunocompromised individuals, particularly those with HIV infection. These conditions include bacillary angiomatosis, peliosis hepatis, and a form of culture-negative endocarditis.
6. Sporotrichosis is also called “Schenck’s disease,” and the causative organism is named Sporothrix schenckii. Who was Schenck?
The disease is named after Bernard R. Schenck, who described the first definitive case of sporotrichosis (in an arm) in which the fungus was also isolated from the patient. Schenck was a second year medical student at Johns Hopkins Hospital when he made his famous discovery. The fungus could not be identified and was sent to Dr. E.F. Smith at the United States Department of Agriculture. Based on the colony appearance and microscopic morphology, Dr. Smith considered the fungus to be a species of Sporotrichium. In 1900, Hektoen and Perkins described a case of sporotrichosis in the finger of a boy who had struck his finger with a hammer. They reported the case as “Refractory subcutaneous abscesses caused by Sporothrix schenckii” and Dr. Schenck’s name became forever associated with this fungal infection. Dr. Schenck did not become a dermatologist and reportedly specialized in obstetrics and gynecology after medical school.
7. What is the difference between Klippel-Trénaunay-Weber syndrome and Klippel-Trénaunay-Parkes-Weber syndrome?
There is no difference. They are examples of eponymy with synonymy; both refer to osteohypertrophic nevus flammeus or angioosteohypertrophy syndrome. The medical literature contains many reports, erroneous but oft-perpetuated, that distinguish the two as different syndromes on the basis of limb-length discrepancies. Weber and Parkes-Weber refer to the same person: Frederick Parkes Weber (1863–1962), an Englishman who was a consummate physician and erudite collector of unusual medical cases.
9. What is ciguatera poisoning?
Ciguatera poisoning is caused by ingestion of ciguatoxin, a tasteless toxin produced by dinoflagellates (Gambierdiscus toxicus). Humans are affected by eating carnivorous fish (such as barracuda or red snapper) that have accumulated the toxin as it is passed along the oceanic food chain. Ciguatera occurs along coral reefs in tropical or warm subtropical waters. Ciguatoxin interferes with sodium channels in mammalian cell membranes. There are a number of gastrointestinal symptoms, but the occasional fatality is usually due to cardiorespiratory involvement.
Lange WR: Ciguatera fish poisoning, Am Fam Physician 50:579–584, 1994.
11. From what is cantharidin made?
Cantharidin (C10H12O4), a vesicant therapy for molluscum contagiosum and warts, is a semipurified extract from blister beetles. The compound induces a blister at the epidermal–dermal junction. Blister beetles, mostly in the family Meloidae, have been used in Asian folk medicine for millennia. In the southern United States, horses are often afflicted with cantharidin toxicity after inadvertently eating the blister beetles that live in mowed alfalfa.
13. Seriously now, cantharidin has been confirmed as an aphrodisiac. Who uses it and how does it work?
Male beetles of the species Neopyrochroa flabellata secrete cantharidin from a gland on their heads as a courtship or prenuptial offering. Females prefer to mate with males who offer cantharidin, which the female then uses to protect her eggs from predacious grubs.