Highlights of the Summer Meeting of the American Academy of Dermatology

Introduction

Despite attending every single Annual Meeting of the American Academy of Dermatology for the past 7 years, I had never been to a Summer Academy meeting before my trip to New York City for this year's meeting. In general, the Summer Academy is more relaxed and informal than the Annual Meeting. The focus of this summer's meeting seemed to be new approaches to common dermatologic ailments: nearly a quarter to a third of the sessions were entitled, "What's New In.... ."

As a practicing dermatologist and dermatopathologist with some clinical research interests, my attendance was limited mostly to topics pertaining to general medical dermatology, although it was apparent that procedural dermatology was well represented at the meeting. The reduced size of the meeting allowed for easy attendance of most sessions, and the location in Manhattan also provided plenty of extracurricular activities to enjoy.

Acne and Rosacea

The treatment of acne and rosacea is a major concern in general dermatology, and at this meeting "hometown" dermatologist Hilary Baldwin, MD, State University of New York Downstate Medical Center, Brooklyn, New York, discussed the recent availability of sustained-release forms of minocycline and doxycycline.^[1,2] Minocycline is often used in the treatment of moderate to severe acne, but its pharmacologic properties can make compliance an issue. Evidence suggests that its anti-inflammatory properties, in addition to any antibacterial effect, are important in acne management,^[3] yet classic dosing schedules lead to high peak blood levels, and teenagers with hectic schedules may find it difficult to take the drug on an empty stomach. Sustained-release minocycline may benefit acne treatment by providing more stable and sustained blood levels,^[4] while the once-daily dosing may be advantageous in the teenage population often afflicted with acne.

Similarly, sustained-release doxycycline has been approved recently by the US Food and Drug Administration (FDA) for the treatment of rosacea. Again, it is the potent anti-inflammatory properties of the tetracycline family of medicines that are being employed. On the horizon, Dr. Baldwin alluded to incyclinide,^[5] a new derivative of tetracycline that is not an antibiotic but is performing well in clinical trials. In the future, this drug may be added to the dermatologist's armamentarium for treating acne and rosacea.

Skin Cancer

Melanoma

During the plenary session, Martin Weinstock, MD, PhD, Brown University, Providence, Rhode Island, informed the membership about the continued rising incidence of melanoma. Particularly alarming was evidence that melanoma incidence is increasing not only among older Americans, for whom safe-sun practices may not have been emphasized, but also among the youngest age groups studied, specifically ages 15 to 30 years. Dr. Weinstock believes that this increase in melanoma is still being propelled by failure to heed warnings about exposure to ultraviolet light.

In particular, evidence from a recent paper suggested that younger youth (11-15 years) seemed to be heeding sun-protection advice, while older youth seemed less responsive to sun-protection education.^[6] Because older teens are more influenced by their peers, compared with younger youth who may be amenable to parental direction, Dr. Weinstock believes this information could be used to design future public education campaigns. Indeed, the results of a study published in 2007 detailing a "Sun-Safe Middle School" program that used a broad range of role models, including peer advocates, demonstrated significant improvements in compliance.^[7]

Nonmelanoma Skin Cancer

There were several interesting posters from Australia presented at the meeting that detailed a new topical medication: PEP005. This topical medicine is derived from the sap of the petty spurge (Euphorbia peplus). While not detailed in the poster, it was known to me that the milky sap of this plant was used in England during the 17th through 19th centuries as a treatment for warts.^[8] The Australian researchers used this particular isolate to treat superficial basal cell skin cancer (sBCC) and actinic keratosis (AK), using daily dosing for 2 days, with approximate 70% and 80% clearance rates, respectively.^[9,10] Adverse effects (eg, erythema, dryness, flaking, scabbing, crusting) were low, and no systemic absorption was detected. Based on these preliminary data, the investigators stated that additional testing is indicated, which may eventually add to the growing armamentarium of topical agents for sBCC and AK.

Preventive Medicine

Human Papilloma Virus (HPV) Vaccine

"The HPV vaccine is the medical breakthrough of the 21st century," announced Stephen K. Tyring, MD, PhD, University of Texas Health Sciences Center, Houston, Texas. The vaccine, which was released in 2006, demonstrates efficacy against HPV subtypes 6 and 11 (involved in 90% of genital warts) and HPV subtypes 16 and 18 (involved in 70% of cervical cancer) and is approved for use in women 9 to 26 years of age.^[11] Clearly impressed with the vaccine, Dr. Tyring noted that it proved 99% effective in studies.^[12] For optimal efficacy, the vaccine must be administered before patients become sexually active. Dr. Tyring also remarked that some patients and their parents have misconceived notions that the vaccine could cause genital warts. This is wholly unfounded because the vaccine is synthetic and contains no live virus.

As a dermatologist with a joint appointment in a sexually transmitted disease clinic sponsored by the Centers for Disease Control and Prevention, I share a great deal of enthusiasm about this vaccine. Yet, to be fair, some experts have taken issue with the cost of the vaccine itself (the highest of any marketed vaccine)^[13] and the financial burden to already stretched state public health budgets should it become a "required vaccination."^[14] However, the cost of vaccination must be balanced with the morbidity and mortality of genital warts and cervical cancer occurring in adult women.

General Medical Dermatology

Nephrogenic Systemic Fibrosis

One of the most surprising medical developments of the last year was the strong association that emerged between exposure to gadolinium-based contrast agents during renal insufficiency and the heretofore unexplained disease nephrogenic systemic fibrosis (NSF). This discovery affected not only dermatology, but also nephrology and radiology. Instrumental in establishing this association was the identification and quantification of gadolinium in the affected tissue of patients with NSF.^[15,16,17]

During the dermatopathology symposium, I described my own work using both electron microscopy and mass spectrometry in studying metals in the skin. Key to the presentation were preliminary data from patients with NSF and high levels of gadolinium in the skin (> 70+ ppm) compared with a small number of foreskin controls from unexposed infants (0 ppm) and even end-stage renal disease and renal transplant patients with exposure to gadolinium but no evidence of NSF (1-2 ppm gadolinium). Clearly it would appear that gadolinium is involved in the process that manifests as fibrosis, but additional investigation will be necessary to elucidate the pathophysiologic mechanism(s), as well as the contributions of any other factors to the disease process.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

Francisco Kerdel, MD, University of Miami, Miami, Florida, presented an interesting discussion on the use of intravenous immunoglobulin (IVIG) in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). While acknowledging that the issue is not settled in the literature, Dr. Kerdel asserted that the discrepancies from individual studies may pertain to the dosages used. He indicated that he believes the best treatment course for TEN is IVIG dosed at 1 g/kg/day for 3 consecutive days.^[18,19] The Miami experience with this medication has been favorable, with mortality significantly less than that predicted. Dr. Kerdel also indicated that the large protein source provided by IVIG may also provide additional benefit to patients with TEN. No specific mention was made of a recently published study from the Netherlands that demonstrated benefit with pulsed intravenous dexamethasone in early SJS, seemingly reviving the debate on early intervention with steroids in this form of the disease.^[20]

Pruritus

All dermatologists are confronted with patients complaining of chronic pruritus unresponsive to antihistamine-based treatments. Gil Yosipovitch, MD, a researcher at Wake Forest University, Chapel Hill, North Carolina, with a particular interest in itch, reviewed 2 major developments that have occurred in the past few months that emphasize the role of prostanoids and g-protein receptors in the manifestation of itch. In the first study, researchers in Japan demonstrated that thromboxane A2 (TXA2), a prostanoid, elicits scratching through a unique thromboxane (TP) receptor.^[21] In mice, blocking of either TXA2 production or TP receptor-binding mitigated itch; this may lead to new therapies for humans as well. In the second study, researchers at Washington University, St. Louis, Missouri, discovered a gene encoding for a gastrin-releasing peptide receptor gene (GRPR) that assists in transmitting signals of itching up the spinal cord to the brain.^[22] This finding will provide an additional target for new anti-itch therapies that are completely independent of the classic histamine-based pathways.

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