P7067Analysis of diagnostic methods for onychomycosis

Aditya Gupta, MD, PhD, Mediprobe Research Inc, London, Ontario, Canada;Fiona Simpson, Mediprobe Research Inc, London, Ontario, Canada

Background: Molecular biology techniques (MBT) have emerged as the newesttechnique for diagnosing onychomycosis; however, they have yet to be systemat-ically compared to the traditional techniques of direct microscopic examination(DME) andmycological culture (MC). Here, we analyze studies that directly comparethe results of these three tests on individual samples to seewhich diagnostic strategyhas the highest predictive value.

Methods: We searched the PubMed database for articles comparing MBT to DMEand/or MC on February 23, 2012. The search was restricted to English languagearticles. Studies were excluded if they had mixed nail and skin samples or if they didnot include results for all of the tests compared. Data for single and 2 test diagnosticstrategies was analyzed using RevMan 5.0 and Meta-DiSc softwares. True positivesrequired confirmation by two test methodologies; true negatives required at leasttwo negative results.

Results: The results for a single test strategy show that DME and MBT have clinicallyuseful positive predictive power (+LR: 4.7, 3.7) and that MC has clinically very usefulpositive predictive power (+LR: 8.7), but that individually none have the requirednegative predictive power to rule out onychomycosis (-LR: 0.15, 0.20, 0.36respectively). DME is the most sensitive (89.7%) and specific (83.7%) individualtest. Culture is highly specific (93.8%), with reduced sensitivity (68.0%), whereasMBT is sensitive (86.9%) with reduced specificity (75.6%). In a two test strategy, withDME/MC or DME/MBT, where a single positive result was indicator of onychomy-cosis, both test strategies had clinically useful positive predictive power (+LR: 3.1,2.1) and negative predictive power (-LR: 0.012, 0.015).

Conclusion: The diagnosis of onychomycosis will continue to require multiple teststrategies, as no single diagnostic method emerges as a criterion standard test. Inaddition, the current diagnostic tests can vary in outcome based on samplingtechnique, so it is critical that care is taken when obtaining clinical samples. DMEhas the highest predictive power and is a rapid and straightforward technique, but itshould be combined with MC or MBT to increase the predictive power. MBT haveshown that they have benefits that are comparable to MC as a secondary technique,and they have the benefit of allowing genome based species identification. Werecommend that any diagnostic strategy for onychomycosis use two tests including aDME technique.

AB126

cial support: None identified.

Commer

P7004Atypical presentation of bilateral lynphatic cutaneous sporotrichosis

Aline Luz, MD, Instituto de Dermatologia Professor Rubem David Azulay, Rio deJaneiro, Brazil; Camila Oliveira, MD, Instituto de Dermatologia Professor RubemDavid Azulay, Rio de Janeiro, Brazil; Fernanda Bongiovani, Instituto deDermatologia Professor Rubem David Azulay, Rio de Janeiro, Brazil; FernandoVargas, MD, Instituto de Dermatologia Professor Rubem David Azulay, Rio deJaneiro, Brazil; Johanna Villarreal, MD, Instituto de Dermatologia ProfessorRubem David Azulay, Rio de Janeiro, Brazil; Jos�e Nery, Instituto deDermatologia Professor Rubem David Azulay, Rio de Janeiro, Brazil; LuzianyAra�ujo, Instituto de Dermatologia Professor Rubem David Azulay, Rio de Janeiro,Brazil

Background: Sporotrichosis is a subacute or chronic infection with cutaneous,mucosal or extracutaneous involment, caused by a fungus named Sporothrixschenckii. In Central and South America, the most cases have reported from Brazil.The most common form of presentation is the cutaneous lymphatic on uppermembers. Inoculation’s mechanism in humans occurs primarily by penetration ofthe fungus into the dermis after injury with sharp objects or, rarely, infected byzoonotic transmission. This report demonstrates an unusual lymphatic cutaneousbilateral features in a housewife’s superior members in the nonendemic area.

Case report: A 60-year-oldwoman born in Niteroi, Rio de Janeiro, Brazil, who reportsthe appearance of erythematous papules with progressive growth of plates on theback of her right hand and her left arm 3 weeks after blunt traumawith plant thornsin her home, with further nodular lesions proximal erythematous violaceous,associates with erythema, swelling and pain, refered topical treatment with creamswithout success. Physical examination: erythematous exulcerated patch located onthe lower third face of the left arm with peripheral pustules associated withviolaceous erythematous nodules following the pathway proximal lymphatic withperipheral erythema. The patient was diagnosed with bilateral cutaneous lymphaticsporotrichosis and was treated with itraconazole 100 mg daily, after 30 days oftreatment the patient improveswith decreased inflammation and reepithelializationof ulcers. The patient’s personal history demonstrates blunt trauma (thorn tree).

Discussion: The most common subcutaneous mycosis is Sporotrichosis. This occursmost frequently in the form of cutaneous lymphatic involvement in superiormembers. The most affected groups are gardeners. The disease is also described aszoonotic transmission (ie, scratching of pets), but can be presented in theimunocompromised patients as a cutaneous spread. The initial lesion may be apapule or nodule that ulcerates, followed by new nodules that appears along theregional lymphatic chain path, reaching to the ganglionar regional chain. This reportemphasizes the importance of an early diagnosis in an atypical presentation as wellas the treatment of esporotrichosis with itraconazole 100 mg daily having goodresponse.

cial support: None identified.

Commer

J AM ACAD DERMATOL

P6976Criteria for onychomycosis mycologic cure: A second look

Mahmoud Ghannoum, PhD, Center for Medical Mycology, University Hospital ofCleveland, Cleveland, OH, United States; Nancy Isham, Center for MedicalMycology, University Hospitals of Cleveland, Cleveland, OH, United States;Veronica Catalano, Center for Medical Mycology, University Hospital ofCleveland, Cleveland, OH, United States

Background: For onychomycosis clinical trials, complete cure is defined as clinicalcure (nail clearing) plus mycologic cure (both negative microscopy and dermato-phyte culture). Approval of new antifungal agents by the FDA for the treatment ofonychomycosis may be negatively impacted by overly stringent rules for definingmycologic cure. Microscopic examination using the most common stainingmethods cannot distinguish between viable and nonviable fungal elements.Because of the slow growth rate of clear nail, direct smears from subungual debrisafter antifungal therapymay still contain fungal hyphae even though mycologic curehas in fact been attained.

Methods: To explore this possibility, we compared the data from 11 national andinternational onychomycosis trials for which we served as the central mycologylaboratory, each of which had obtained samples following at least 48 weeks oftreatment. All samples had been processed for direct fluorescent microscopy anddermatophyte culture. In addition, to determine whether morphologic changescould be observed after extended exposure to study drug, we examined 166 last-visitsamples under both white and UV light.

Results: Of the 3664 samples collected at final visits, 2735 were culture-negative fordermatophytes. Of these culture negative samples, nearly 71% (n ¼ 1938) demon-strated fungal elements on direct examination. From the set of samples examined formorphologic changes, we were able to identify hyphal damage, including breakageand distortion, in 92 direct smears (55%). These morphologic changes may beindicative of nonviable fungal cells.

Conclusion: In our experience, a high rate of subungual debris samples collectedfrom subjects enrolled in lengthy onychomycosis trials remained direct smear-positivewhile converting to dermatophyte-negative culture. In addition, evidence ofmorphologic hyphal damage suggests that these late-visit microscopic results may befalse-positives. Because this ‘‘double-positive’’ criteria for mycologic cure may behighly impacting the development of new onychomycosis drugs, additional studiesare warranted to determine whether hyphal damage should be taken into consid-eration as part of the criteria for microscopy.

cial support: None identified.

Commer

P5907Cutaneous phaeohyphomycosis in an immunocompromised host

Evelyn Tay, National Skin Center, Singapore; Jiun Yit Pan, National Skin Center,Singapore; Joyce Lee, National Skin Center, Singapore

Phaeohyphomycoses refer to infections caused by dematiaceous fungi in whichfungi are present as yeast-like cells or hyphal elements. Based on the Fader andMcGinnis classification, phaeohyphomycoses can be subdivided into (i) superficial,(ii) cutaneous, (iii) subcutaneous and (iv) systemic. We herein report a case ofcutaneous phaeohyphomycosis of the right forearm in a 72 year old patient with lowgrade B-cell lymphoma. Tissue fungal cultures yielded 2 fungi, namely Exophialajeanselmei and Cladophialophora species. The infection was successfully treatedwith 3 months of oral itraconazole. We seek to highlight phaeohyphomycoses as anemerging mycoses in immunocompromised individuals, especially among solidorgan transplant recipients on long term immunosuppressants and patients withhaematological malignancies. This case also serves to emphasize that physiciansshould maintain a high clinical suspicion for unusual skin signs in immunocompro-mised individuals as they are more prone to developing opportunistic skininfections.

cial support: None identified.

Commer

APRIL 2013