Leong kin Fon

Dr. Leong kin Fon


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 October 2021 in Drugs in Context
Verified
Journal Article
Open access
Alexander K.C. LeungAlexander K.C. Leung
Alexander K.C. Leung
BBBenjamin Barankin
Benjamin Barankin
JLJoseph M Lam
Joseph M Lam
LFLeong kin Fon
Leong kin Fon
Kam Lun Ellis HonKam Lun Ellis Hon
Kam Lun Ellis Hon
Acne vulgaris is the most common skin disease that can lead to disfigurement and psychological distress. This article aims to provide a narrative updated review on the management of acne vulgaris. A PubMed search was performed with Clinical Queries using the key term “acne”. The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies and reviews. The search was restricted to articles published in English. Treatments of acne include proper skin care, topical medications, oral medications and procedural therapies. Topical agents are the first-line treatment for mild-to-moderate acne and can be used as combination therapy for more severe acne. Systemic therapies are usually prescribed for the initial treatment of moderate-to-severe acne as well as for acne that is refractory to topical therapies. Topical retinoids are the drugs of choice for the treatment and maintenance therapy of patients with mild-to-moderate acne vulgaris. Depending on the severity of the acne, topical retinoids may be used alone or in combination with benzoyl peroxide and topical or oral antibiotics. Oral antibiotics are an important therapy for inflammatory acne unresponsive to topical therapy. Neither topical nor oral antibiotics should be used as monotherapy. Oral contraceptives and/or spironolactone are useful for many women with acne. Oral isotretinoin is the drug of choice for severe, extensive, nodular acne vulgaris but is also often used in moderate cases where scarring is evident, acne-related psychosocial distress is significant or other treatment modalities have failed.

30 March 2020 in Recent Patents on Inflammation & Allergy Drug Discovery
Verified
Journal Article
Open access
PDF file
Alexander K.C. LeungAlexander K.C. Leung
Alexander K.C. Leung
JLJoseph M. Lam
Joseph M. Lam
LFLeong kin Fon
Leong kin Fon
Kam Lun Ellis HonKam Lun Ellis Hon
Kam Lun Ellis Hon
BBBenjamin Barankin
Benjamin Barankin
AWAlex H.C. Wong
Alex H.C. Wong
Background : Onychomycosis is a common fungal infection of the nail.Objective: The study aimed to provide an update on the evaluation, diagnosis, and treatment of onychomycosis.Methods: A PubMed search was completed in Clinical Queries using the key term “onychomycosis”. The search was conducted in May 2019. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. The search was restricted to English literature. Patents were searched using the key term “onychomycosis” in www.freepatentsonline.com.Results : Onychomycosis is a fungal infection of the nail unit. Approximately 90% of toenail and 75% of fingernail onychomycosis are caused by dermatophytes, notably Trichophyton mentagrophytes and Trichophyton rubrum. Clinical manifestations include discoloration of the nail, subungual hyperkeratosis, onycholysis, and onychauxis. The diagnosis can be confirmed by direct microscopic examination with a potassium hydroxide wet-mount preparation, histopathologic examination of the trimmed affected nail plate with a periodic-acid-Schiff stain, fungal culture, or polymerase chain reaction assays. Laboratory confirmation of onychomycosis before beginning a treatment regimen should be considered. Currently, oral terbinafine is the treatment of choice, followed by oral itraconazole. In general, topical monotherapy can be considered for mild to moderate onychomycosis and is a therapeutic option when oral antifungal agents are contraindicated or cannot be tolerated. Recent patents related to the management of onychomycosis are also discussed.Conclusion: Oral antifungal therapies are effective, but significant adverse effects limit their use. Although topical antifungal therapies have minimal adverse events, they are less effective than oral antifungal therapies, due to poor nail penetration. Therefore, there is a need for exploring more effective and/or alternative treatment modalities for the treatment of onychomycosis which are safer and more effective.

21 January 2021 in Current Pediatric Reviews
Verified
Journal Article
Closed access
PDF file
Alexander K.C. LeungAlexander K.C. Leung
Alexander K.C. Leung
BBBenjamin Barankin
Benjamin Barankin
LFLeong kin Fon
Leong kin Fon
Background: Henoch-Schönlein purpura (HSP) is an IgA-mediated systemic smallvessel vasculitis with a predilection for the skin, gastrointestinal tract, joints, and kidneys. It is the most common form of systemic vasculitis in children. Objective: The study aimed to familiarize physicians with the etiopathogenesis, clinical manifestations, evaluation, and management of children with Henoch-Schönlein purpura. Methods : A PubMed search was conducted in January 2020 in Clinical Queries using the key terms “Henoch-Schönlein purpura” OR “IgA vasculitis” OR “anaphylactoid purpura”. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. This paper is based on, but not limited to, the search results. Results: Globally, the incidence of HSP is 10 to 20 cases per 100, 000 children per year. Approximately 90% of cases occur in children between 2 and 10 years of age, with a peak incidence at 4 to 7 years. The diagnosis should be based on the finding of palpable purpura in the presence of at least one of the following criteria, namely, diffuse abdominal pain, arthritis or arthralgia, renal involvement (hematuria and/or proteinuria), and a biopsy showing predominant IgA deposition. Most cases are self-limited. The average duration of the disease is 4 weeks. Long-term complications are rare and include persistent hypertension and end-stage kidney disease. Therapy consists of general and supportive measures as well as treatment of the sequelae of the vasculitis. Current evidence does not support the universal treatment of HSP patients with corticosteroids. Oral corticosteroids may be considered for HSP patients with severe gastrointestinal pain and gastrointestinal hemorrhage. Conclusions: Most cases of HSP have an excellent outcome, with renal involvement being the most important prognostic factor in determining morbidity and mortality. Unfortunately, early steroid treatment does not reduce the incidence and severity of nephropathy in children with HSP. In HSP children who have severe nephritis or renal involvement with proteinuria of greater than 3 months, an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker should be considered in addition to corticosteroids to prevent and/or limit secondary glomerular injury.

30 March 2020 in Recent Patents on Inflammation & Allergy Drug Discovery
Verified
Journal Article
Closed access
PDF file
Alexander K.C. LeungAlexander K.C. Leung
Alexander K.C. Leung
Kam Lun Ellis HonKam Lun Ellis Hon
Kam Lun Ellis Hon
LFLeong kin Fon
Leong kin Fon
BBBenjamin Barankin
Benjamin Barankin
JLJoseph M. Lam
Joseph M. Lam
Background: Tinea capitis is a common and, at times, difficult to treat, fungal infection of the scalp. Objective: This article aimed to provide an update on the evaluation, diagnosis, and treatment of tinea capitis. Methods: A PubMed search was performed in Clinical Queries using the key term “tinea capitis”. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article. : Patents were searched using the key term “tinea capitis” at www.freepatentsonline.com. Results: Tinea capitis is most often caused by Trichophyton tonsurans and Microsporum canis. The peak incidence is between 3 and 7 years of age. Non-inflammatory tinea capitis typically presents as fine scaling with single or multiple scaly patches of circular alopecia (grey patches); diffuse or patchy, fine, white, adherent scaling of the scalp resembling generalized dandruff with subtle hair loss; or single or multiple patches of well-demarcated area (s) of alopecia with fine-scale, studded with broken-off hairs at the scalp surface, resulting in the appearance of “black dots”. Inflammatory variants of tinea capitis include kerion and favus. Dermoscopy is a highly sensitive tool for the diagnosis of tinea capitis. The diagnosis can be confirmed by direct microscopic examination with a potassium hydroxide wetmount preparation and fungal culture. It is desirable to have mycologic confirmation of tinea capitis before beginning a treatment regimen. Oral antifungal therapy (terbinafine, griseofulvin, itraconazole, and fluconazole) is considered the gold standard for tinea capitis. Recent patents related to the management of tinea capitis are also discussed. Conclusion: Tinea capitis requires systemic antifungal treatment. Although topical antifungal therapies have minimal adverse events, topical antifungal agents alone are not recommended for the treatment of tinea capitis because these agents do not penetrate the root of the hair follicles deep within the dermis. Topical antifungal therapy, however, can be used to reduce transmission of spores and can be used as adjuvant therapy to systemic antifungals. Combined therapy with topical and oral antifungals may increase the cure rate.

14 November 2022 in Drugs in Context
Verified
Journal Article
Open access
Alexander K.C. LeungAlexander K.C. Leung
Alexander K.C. Leung
BBBenjamin Barankin
Benjamin Barankin
JLJoseph M Lam
Joseph M Lam
LFLeong kin Fon
Leong kin Fon
Kam Lun Ellis HonKam Lun Ellis Hon
Kam Lun Ellis Hon
Tinea versicolor is a common superficial fungal infection of the skin with various clinical manifestations. This review aims to familiarize physicians with the clinical features, diagnosis and management of tinea versicolor. A search was conducted in July 2022 in PubMed Clinical Queries using the key terms “tinea versicolor” OR “pityriasis versicolor”. The search strategy included all clinical trials, observational studies and reviews published within the past 10 years. Tinea versicolor is caused by Malassezia species, notably M. globosa, M. furfur and M. sympodialis. The condition is characterized by scaly hypopigmented or hyperpigmented macules/patches, primarily located on the upper trunk, neck and upper arms. The diagnosis is usually based on characteristic clinical features. If necessary, a potassium hydroxide preparation test can be performed to reveal numerous short, stubby hyphae intermixed with clusters of spores. Most patients with tinea versicolor respond to topical antifungal therapy, which has a better safety profile (fewer adverse events, fewer drug interactions) and lower cost compared to systemic treatment and is therefore the treatment of choice. Oral antifungal therapy is typically reserved for patients with extensive disease, frequent recurrences or disease that is refractory to topical therapy. Advantages of oral antifungal therapy include increased patient compliance, shorter duration of treatment, increased convenience, less time involved with therapy and reduced recurrence rates. On the other hand, oral antifungal therapy is associated with higher cost, greater adverse events and potential drug–drug interactions and is therefore not the first-line treatment for tinea versicolor. Long-term intermittent prophylactic therapy should be considered for patients with frequent recurrence of the disease. Selection of antifungal agents depends on several factors, including efficacy, safety, local availability, ease of administration, likelihood of compliance and potential drug interactions of the antifungal agent.

2 April 2021 in Current Pediatric Reviews
Verified
Journal Article
Closed access
PDF file
Alexander K.C. LeungAlexander K.C. Leung
Alexander K.C. Leung
JLJoseph M. Lam
Joseph M. Lam
LFLeong kin Fon
Leong kin Fon
Kam Lun Ellis HonKam Lun Ellis Hon
Kam Lun Ellis Hon
Background: Infantile hemangiomas are the most common vascular tumors of infancy, affecting up to 12% of infants by the first year of life. Objective: To familiarize physicians with the natural history, clinical manifestations, diagnosis, and management of infantile hemangiomas. Methods: A Pubmed search was conducted in November 2019 in Clinical Queries using the key term "infantile hemangioma". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article. Results: The majority of infantile hemangiomas are not present at birth. They often appear in the first few weeks of life as areas of pallor, followed by telangiectatic or faint red patches. Then, they grow rapidly in the first 3 to 6 months of life. Superficial lesions are bright red, protuberant, bosselated, or with a smooth surface, and sharply demarcated. Deep lesions are bluish and dome-shaped. Infantile hemangiomas continue to grow until 9 to 12 months of age, at which time the growth rate slows down to parallel the growth of the child. Involution typically begins by the time the child is a year old. Approximately 50% of infantile hemangiomas will show complete involution by the time a child reaches age 5; 70% will have disappeared by age 7; and 95% will have regressed by 10 to 12 years of age. The majority of infantile hemangiomas require no treatment. Treatment options include oral propranolol, topical timolol, and oral corticosteroids. Indications for active intervention include hemorrhage unresponsive to treatment, impending ulceration in areas where serious complications might ensue, interference with vital structures, life- or function-threatening complications, and significant disfigurement. Conclusion: Treatment should be individualized, depending upon the size, rate of growth, morphology, number, and location of the lesion (s), existing or potential complications, benefits and adverse events associated with the treatment, age of the patient, level of parental concern, and the physician's comfort level with the various treatment options. Currently, oral propranolol is the treatment of choice for high-risk and complicated infantile hemangiomas. Topical timolol may be considered for superficial infantile hemangiomas that need to be treated and for complicated infantile hemangiomas in patients at risk for severe adverse events from oral administration of propranolol.