Phuong Khuu, M.D., is a Clinical Assistant Professor in Pediatric Dermatology at Lucile Packard Children’s Hospital. Her clinical interests include children with complex dermatologic diseases and epidermolysis bullosa. Her research interest is in clinical management of epidermolysis bullosa.
- Pediatric Dermatology
- Complex Dermatologic Diseases
- Epidermolysis Bullosa
Clinical Assistant Professor, Dermatology
Medical Education: University of California at San Francisco School of Medicine (2002) CA
Residency: Stanford University Hospital and Clinics - Dermatology Department (2010) CA
Residency: Univ of California San Francisco (2005) CA
Internship: Univ of California San Francisco (2003) CA
Fellowship: Stanford University (2007) CA
Board Certification: Dermatology, American Board of Dermatology (2011)
Gene Transfer for Recessive Dystrophic Epidermolysis Bullosa
This trial will create a skin graft, which the investigators call "LEAES," using the patient's own skin cells that have been genetically engineered in the lab to express a missing protein called type VII collagen. The corrected cells will be transplanted back to the patient.
Stanford is currently not accepting patients for this trial. For more information, please contact Yana Dutt-Singkh, 650-721-7166.
Grafting of Epidermolysis Bullosa Wounds Using Cultured Revertant Autologous Keratinocytes
The term epidermolysis bullosa (EB) is used to describe a group of genetic skin diseases associated with skin weakness, blisters, and chronic wounds. "Revertant mosaicism" means that there are two genetically different populations of cells due to spontaneous mutations. Some EB patients have normal, non-fragile skin patches which may be areas of revertant mosaicism. In the revertant areas, the proteins function normally, like non-EB skin. In this study, we plan to culture cells from the revertant areas and graft them on to the wounded areas.
Stanford is currently not accepting patients for this trial. For more information, please contact Emily S Gorell, MS, 650-721-7166.
Safety and Wound Outcomes Following Genetically Corrected Autologous Epidermal Grafts in Patients With Recessive Dystrophic Epidermolysis Bullosa.
2016; 316 (17): 1808-1817
Recessive dystrophic epidermolysis bullosa (RDEB) is a devastating, often fatal, inherited blistering disorder caused by mutations in the COL7A1 gene encoding type VII collagen. Support and palliation are the only current therapies.To evaluate the safety and wound outcomes following genetically corrected autologous epidermal grafts in patients with RDEB.Single-center phase 1 clinical trial conducted in the United States of 4 patients with severe RDEB with a measured area of wounds suitable for grafting of at least 100 cm2. Patients with undetectable type VII collagen keratinocyte expression were excluded.Autologous keratinocytes isolated from biopsy samples collected from 4 patients with RDEB were transduced with good manufacturing practice-grade retrovirus carrying full-length human COL7A1 and assembled into epidermal sheet grafts. Type VII collagen gene-corrected grafts (approximately 35 cm2) were transplanted onto 6 wounds in each of the patients (n = 24 grafts).The primary safety outcomes were recombination competent retrovirus, cancer, and autoimmune reaction. Molecular correction was assessed as type VII collagen expression measured by immunofluorescence and immunoelectron microscopy. Wound healing was assessed using serial photographs taken at 3, 6, and 12 months after grafting.The 4 patients (mean age, 23 years [range, 18-32 years]) were all male with an estimated body surface area affected with RDEB of 4% to 30%. All 24 grafts were well tolerated without serious adverse events. Type VII collagen expression at the dermal-epidermal junction was demonstrated on the graft sites by immunofluorescence microscopy in 9 of 10 biopsy samples (90%) at 3 months, in 8 of 12 samples (66%) at 6 months, and in 5 of 12 samples (42%) at 12 months, including correct type VII collagen localization to anchoring fibrils. Wounds with recombinant type VII collagen graft sites displayed 75% or greater healing at 3 months (21 intact graft sites of 24 wound sites; 87%), 6 months (16/24; 67%), and 12 months (12/24; 50%) compared with baseline wound sites.In this preliminary study of 4 patients with RDEB, there was wound healing in some type VII collagen gene-corrected grafts, but the response was variable among patients and among grafted sites and generally declined over 1 year. Long-term follow-up is necessary for these patients, and controlled trials are needed with a broader range of patients to better understand the potential long-term efficacy of genetically corrected autologous epidermal grafts.clinicaltrials.gov Identifier: NCT01263379.
View details for DOI 10.1001/jama.2016.15588
View details for PubMedID 27802546
Purified Type I Collagen Wound Matrix Improves Chronic Wound Healing in Patients with Recessive Dystrophic Epidermolysis Bullosa
2015; 32 (2): 220-225
Recessive dystrophic epidermolysis bullosa is a severe genetic blistering skin condition resulting in chronic wounds. Nonhealing wounds were treated over 8 weeks using a reconstituted natural purified type I collagen skin substitute. Chronic wounds were defined as nonhealing wounds present for longer than 6 months. For each patient, two chronic wounds were identified and randomized into a control or treatment group. Both groups received standard-of-care wound dressings. The treatment group received an additional type I collagen skin substitute. Wound size was measured at baseline and weeks 1, 4, and 8. Pain, pruritus, and burning and stinging were assessed. Wound cultures were obtained at baseline and thereafter as was considered clinically relevant. Ten subjects were enrolled; seven completed the study. Six subjects showed a positive response to the type I collagen skin substitute. Three subjects demonstrated full wound reepithelialization. Wounds treated using the collagen skin substitute showed statistically significantly greater improvement. Average scores for pruritus and pain decreased significantly. Reconstituted natural purified type I collagen skin substitutes improved the healing of chronic wounds and may be a valuable addition to the epidermolysis bullosa wound care arsenal.
View details for DOI 10.1111/pde.12492
View details for Web of Science ID 000351747500017
View details for PubMedID 25557742
Treatment of keratitis-ichthyosis-deafness (KID) syndrome in children: a case report and review of the literature
2015; 28 (2): 89-93
Keratitis-ichthyosis-deafness (KID) syndrome is a rare hereditary cornification disorder resulting from mutations in connexin 26, a protein important for intercellular communication. In addition to the characteristic clinical triad of congenital bilateral sensorineural hearing loss, keratitis, and erythrokeratoderma, affected individuals also suffer from chronic bacterial and fungal infections and have an increased risk of benign and malignant cutaneous tumors. Treatments with antibiotics, antifungals, and systemic retinoids have been reported with variable response. Ocular and skeletal toxicity from prolonged exposure to systemic retinoids is a major concern especially in children. We report a case of a 7-year-old boy with KID syndrome complicated by frequent infections who responded well to acitretin 0.5-1.0 mg/kg/day. The patient had significant improvement of the hyperkeratosis on the scalp, trunk, and extremities within 4 weeks after initiating treatment. The patient has been on treatment for over a year without notable ocular, skeletal, or laboratory side effects. A review of the literature focusing on therapeutic options for KID syndrome and concerns about safety and tolerability is presented.
View details for DOI 10.1111/dth.12192
View details for Web of Science ID 000352630800010
An open-label study to evaluate sildenafil for the treatment of lymphatic malformations.
Journal of the American Academy of Dermatology
2014; 70 (6): 1050-1057
Lymphatic malformations can be challenging to treat. Mainstay interventions including surgery and sclerotherapy are invasive and can result in local recurrence and complications.We sought to assess the effect of 20 weeks of oral sildenafil on reducing lymphatic malformation volume and symptoms in children.Seven children (4 boys, 3 girls; ages 13-85 months) with lymphatic malformations were given oral sildenafil for 20 weeks in this open-label study. The volume of the lymphatic malformation was calculated blindly using magnetic resonance imaging performed before and after 20 weeks of sildenafil. Lymphatic malformations were assessed clinically on weeks 4, 12, 20, and 32. Both the physician and parents evaluated the lymphatic malformation in comparison with baseline.Four subjects had a lymphatic malformation volume decrease (1.0%-31.7%). In 2 subjects, despite a lymphatic malformation volume increase (1.1%-3.7%), clinical improvement was noted while on sildenafil. One subject had a 29.6% increase in lymphatic malformation volume and no therapeutic response. Lymphatic malformations of all 6 subjects who experienced a therapeutic response on sildenafil softened and became easily compressible. Adverse events were minimal.A randomized controlled trial will be necessary to verify the effects of sildenafil on lymphatic malformations.Sildenafil can reduce lymphatic malformation volume and symptoms in some children.
View details for DOI 10.1016/j.jaad.2014.02.005
View details for PubMedID 24656411
Rapidly Involuting Congenital Hemangioma Associated with Profound, Transient Thrombocytopenia
2014; 31 (3): 402-404
Rapidly involuting congenital hemangioma (RICH) is an uncommon, often high-flow vascular tumor that presents at birth and involutes within the first year of life. It is clinically and histologically distinct from infantile hemangioma, kaposiform hemangioendothelioma, and tufted angioma, the latter two being associated with Kasabach-Merritt phenomenon. We present a female infant with RICH and profound, transient thrombocytopenia and review the extent and clinical course of thrombocytopenia in the context of congenital vascular tumors.
View details for DOI 10.1111/j.1525-1470.2012.01827.x
View details for Web of Science ID 000334884300044
View details for PubMedID 22937785
Multiple Eruptive Pilomatricomas in a 9-year-Old Boy with Glioblastoma.
2013; 30 (6): 756-758
A 9-year-old male presented to our dermatology clinic with a recent history of developing numerous cutaneous pilomatricomas, and was subsequently discovered to have sustained a recurrence of his glioblastoma multiforme. Immunohistochemical staining of a representative pilomatricoma and his original brain tumor revealed upregulation and nuclear localization of beta-catenin, a sign associated with poor prognosis in glioblastoma. We hypothesize that the development of multiple pilomatricomas may have been a hallmark of this patient's tumor recurrence and provide support for a recent report of an association between multiple pilomatricomas and gliomatosis cerebri.
View details for DOI 10.1111/j.1525-1470.2011.01714.x
View details for PubMedID 22304393
Clofarabine in refractory Langerhans cell histiocytosis
PEDIATRIC BLOOD & CANCER
2008; 51 (5): 703-706
Patients with multi-system Langerhans cell histiocytosis (LCH) who progress on frontline therapy have a dismal outcome. Responses to cladribine have been reported in relapsed LCH, but there are no well defined salvage regimens for LCH is refractory to therapy. The next generation deoxyadenosine analog, clofarabine, has demonstrated activity in patients with leukemia that is refractory to salvage regimens, including other nucleotide congeners; however, no experience exist on the use of clofarabine in LCH. In this report we describe significant single agent activity of clofarabine in disseminated LCH refractory to salvage regimens, including cladribine.
View details for DOI 10.1002/pbc.21668
View details for Web of Science ID 000259465400033
View details for PubMedID 18623218