Pinpoint papular variant of polymorphous light eruption: clinical and pathological correlation.

BACKGROUND: Polymorphous light eruption (PMLE) is the most common chronic idiopathic photodermatosis usually manifesting as a papular eruption along with several other morphological variants including a pinpoint papular variant. METHODS AND MATERIALS: Between June 1998 and August 2003, 10 PMLE patients presented to the Department of Dermatology at Henry Ford Hospital with complaints of a pruritic pinpoint papular eruption associated with sun exposure. In six patients skin biopsies were performed along with a detailed history and complete skin examination. We correlated the histology with the clinical course of disease corresponding to acute and subacute disease presentation. We also performed immunohistochemistry on three cases to study the immunophenotype in PMLE. RESULTS: The clinical, histologic and immunostain findings are summarized. Acute: Clinically pinpoint papules and vesicles, some with erythematous base, were seen. Histology showed focal vesicle formation, spongiosis, oedema, red blood cells extravasation, and superficial and deep perivascular and interstitial lymphocytic infiltrate with occasional eosinophils. Subacute: Clinically pinpoint papules with or without erythema were seen. Histology of the pinpoint lesion showed a nodular collection of lymphocytes and histiocytes with claw-like extension of epidermal rete ridges at the lateral boundaries of the lesion. Overlying epidermal atrophy with adjacent spongiosis, exocytosis, oedema and a superficial perivascular lymphocytic infiltrate and parakeratosis was also observed. The histologic differential diagnosis included lichen nitidus. Immunohistochemical stains revealed the following results: CD8, CD68 positive, CD4 variable (strongly positive to negative) and S-100 negative. CONCLUSION: (i) Pinpoint papular variant of PMLE is a distinct entity, which shows characteristic histology corresponding to the clinical course of the disease (acute and subacute). (ii) The histologic and immunophenotypic differential diagnosis of this variant during the subacute phase includes lichen nitidus.

Effects of modified sample collection technique on fungal culture yield: nail clipping/scraping versus microdrill.

OBJECTIVE: Onychomycosis requires accurate diagnosis but fungal culture yield is frequently low by routine sampling techniques. The aim of this study was to investigate the utility of nail plate/subungual microdrilling as an alternative to conventional nail clipping/subungual scraping. METHODS: Patients with clinical evidence of onychomycosis (n=46) were prospectively evaluated for fungal potassium hydroride (KOH) microscopy and culture comparing two sampling techniques: nail clipping versus microdrilling. RESULTS: Fungal cultures were positive in 48% with 2 additional cases detected by combining both methods. KOH microscopy was positive in 17% cases. Specimen obtained via the microdrill technique gave consistent heavier fungal growth on culture media. Candida species were the most common isolates (82.7% of cases) and were negative on KOH microscopy in 95 % of culture proven cases. The microdrill technique yielded consistent heavier growth on culture media CONCLUSION: Microdrill technique improves laboratory diagnosis and ultimately treatment of onychomycosis, particularly in patients with repeated KOH microscopy and culture failure despite strong clinical suspicion.

p16INK4a expression in actinic keratosis and Bowen's disease.

BACKGROUND: Progression of cutaneous squamous neoplasms from actinic keratosis (AK) to Bowen's disease (BD; squamous cell carcinoma in situ) has important implications for clinical management and treatment, thus requiring accurate diagnosis. p16INK4a is a cell cycle regulatory tumour suppressor protein that negatively regulates D-type cyclins in the G1 cell cycle phase via intimate interplay with the retinoblastoma gene. Expression of a paraffin-reactive p16INK4a marker has recently been shown to increase in cervical squamous neoplasms as lesions progress from low-grade dysplasia to squamous cell carcinoma in situ. p16INK4a expression in the progression of squamous cutaneous neoplasia, however, has not been evaluated. OBJECTIVES: To evaluate p16INK4a expression in the progression of squamous cutaneous neoplasia. METHODS: Biopsies of 203 squamous cutaneous neoplasms with unequivocal features of AK (n = 87) and BD (n = 116) as well as a benign squamous control group (verruca vulgaris: n = 10; seborrhoeic keratosis: n = 11; scar tissue: n = 8) obtained between January and December 2001 at Henry Ford Hospital (Detroit, MI, U.S.A.) were immunostained for p16INK4a (Dako; clone E6H4; dilution 1 : 50) using large core (1.5 mm) tissue microarray analysis. Nuclear/cytoplasmic immunoreactivity in > 10% of neoplastic cells was considered positive. RESULTS: Of 203 cases, 166 (81.8%) were interpretable (AK 59; BD 107). Mean patient age was 71.0 years (range 33-93); 57% were male. Sites of involvement were: head and extremities 75.9%, trunk/buttocks 21.7%, genital region 2.4%. p16INK4a immunostaining was positive in 90 of 107 (84.1%) BD cases, four of 59 (6.8%) AK cases and none of 29 benign squamous controls. The sensitivity and specificity of p16INK4a for a diagnosis of BD (vs. benign squamous controls/AK) was 84.1% and 95.5%, respectively (P < 0.0001, Fisher's exact test, two-sided). CONCLUSIONS: p16INK4a is a sensitive and specific marker for distinguishing BD from AK/benign squamous cutaneous lesions and may be helpful as an adjunct to histomorphology in the diagnosis and appropriate clinical management of these lesions.

Changing pattern of antimicrobial susceptibility of organisms causing community acquired urinary tract infections.

OBJECTIVE: To assess common organisms causing Urinary Treat Infection (UTI) in this community and to see antimicrobial susceptibility pattern of these isolates. DESIGN: Prospective study on urine samples. SETTING: Tertiary care hospital in Karachi. METHODS: Over a period of 8 years (1990-97) 9,892 urine samples grew significant bacteriuria for various organisms. All Gram negative rods and entercocci was identified by using API 20E and API 32 strips respectively. Staphylococci were identified by catalase, coagulase and D'Nase tests. Antimicrobial sensitivity testing of all isolates was performed on Diagnostic Sensitivity Test plates by Kerby Bauer method. The discs used were ampicillin, trimethoprim-sulfamethoxazole, cefotaxime, ceftriaxone, aztreonam, ofloxacin, carbenicillin, amikacin, gentamicin, penicillin, clindamycin, methicillin, vancomycin, ceftazidime, cefuroxime, Nalidixic acid, pipemedic acid and Nitrofurantoin. RESULTS: Our results indicate that E. coli and Klebsiella aerogenes are the most common organisms causing UTI in this community. Other organisms involved are Pseudomonas aeroginosa, Enterobacter species, Enterococcus, Proteus mirabillus, Staphylococcus aureus and Staphylococcus saprophyticus. Organisms resistant to various antimicrobial agents such as gentamicin, Amikacin, Ofloxacin, Cefotaxime and Ceftazidime are increasing. CONCLUSION: In conclusion, E. coli and Klebsiella aerogenes are the most common organisms causing UTI in this community. Pattern of antibiotic susceptibility to first line antibiotics is changing. Antimicrobial susceptibility testing of all isolates is crucial for the treatment of UTI.