Locations
Palo Alto Medical Foundation
Palo Alto, CA
About
Bio
Board certified dermatologist. I specialize in skin cancer detection, skin cancer surgeries and cosmetic dermatology, including lasers, Botox, and fillers. I also see general pediatric and adult dermatology including eczema, acne, rosacea, psoriasis, rashes, and other hair, nail and skin diseases.
SpecialtiesDoctors may have more than one area of specialty interest. Board certification in a specialty area means the doctor has completed formal training and has practice experience in that specialty, and has passed the certification examination from the corresponding accredited medical specialty board.
Doctors may have more than one area of specialty interest. Board certification in a specialty area means the doctor has completed formal training and has practice experience in that specialty, and has passed the certification examination from the corresponding accredited medical specialty board.
Dermatology
Languages spoken
English
Doctor Q&A
212 Answers
1 Agree
The number of answers this doctor has agreed with.
A 27-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Terbinafine: If you are certain that you have "ring worm", these are fungal infections that are primarily due to dermatophytes called t. Rubrum. I find that otc t... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6k viewsReviewed >2 years ago
A 34-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Moisturize: This depends of what is the cause of itching. In general, itching is a sign of inflammation. This could be a result of medications, allergic exposure... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Avoid allergens: Keeping your skin moist with bland lotions or ointments is essential. Common avoidable topical allergens include fragrances (organic or not), cocamid... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 24-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Antibiotics target bacteria. Athletes foot is a fungal infection, which responds to antifungals.
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Direct contact: Impetigo spreads by direct skin to skin contact.
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 24-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Keratosis pilaris: Keratosis pilaris (rough pink bumps on upper arms and thighs) are thought to be in the spectrum of eczema with very dry skin and plugging of follicles... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Ichthyosis: Ichthyosis (fish scale disease) is an inherited condition characterized by dry scaly skin as a result in defective skin barrier function. The most com... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Multiple: Melanoma risk factors include fair skin, history of sunburns, excessive uv exposure such as from tanning beds, living near the equator or at higher el... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
See specialist: This is an important question to discuss with your dermatologist. If the melanoma is 1-4mm thick, sln biopsy is often recommended. Between 0.7-1mm d... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Yes: Patients with psoriasis have a higher risk of developing skin cancers and cardiovascular disease. For this reason, it is recommended that those with ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.2k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Photorejuvenation: Ipl is a filtered light device that is effective in removing brown spots and blood vessels, good for treating sun damaged, acne and rosacea skin. With... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Exfoliants: Products containing salicylic (beta hydroxy) acids or Alpha hydroxy acids help acne skin. This may be in the form of face washes or leave-on products... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Rosacea is a chronic inflammatory condition that waxes and wanes. It usually begins in adulthood, and when papules develop, some call it "adult acne"... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Yes: Smoking causes poor wound healing after any invasive procedure such as surgery, laser resurfacing, liposuction, etc..., including scar revision and mo... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Sal acid and Tar: Psoriatic scalp often is also colonized by a common yeast called pityrosporum ovale, which is the same yeast that causes dandruff. Treatment involves ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.2k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Albinism is a genetic pigmentary disorder. The genetic defect that affects enzymes that are involving in pigment (melanin) production or distributive... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Both immunologic: Psoriasis and eczema are both immunological conditions that cause inflammation in the skin. Eczema is histamine driven and is related to hay fever and... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 22-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Exfoliation: Chemical peels removes layers of skin. The strength/chemical determines the depth of the peel. It is generally used to cosmetically removed brown sp... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: We don't fully understand the pathophysiology of vitiligo. It is considered an autoimmune disorder, and sometimes associated with systemic autoimmune... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 22-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Sometimes...: We generally talk about lupus in 2 categories: systemic and cutaneous (localized in skin). A subtype of cutaneous lupus called discoid lupus can caus... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsAnswered >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
See following link : http://www.aad.org/skin-conditions/skin-cancer-detection/about-skin-self-exams/how-to-examine-your-skin.
Created for people with ongoing healthcare needs but benefits everyone.
6.5k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Oral antihistamines: Eczema is an inflammatory disorder driven by excessive histamine release, much like asthma and hay fever. Taking oral antihistamines, such as Claritin... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.4k viewsReviewed >2 years ago
A 21-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Psoriasis is an inflammatory disorder that is inherited, although sporatic cases also occur. There is no way of preventing psoriasis from developing.... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.2k viewsReviewed >2 years ago
A 43-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Rosacea is an inherited condition characterized by extra sensitive skin, flushing, dilated blood vessels, inflammatory bumps that mimic acne, and enla... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.4k viewsReviewed >2 years ago
A 40-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Topical antibiotic: The bacteria that's commonly the cause of impetigo is staph aureus, which responds to prescription topical antibiotics. If your doctor determines tha... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 37-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Direct contact: Cold sores or herpes simplex virus infections. It is spread by direct contact with actively flared blistering lesions.
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 37-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Yeast: Dandruff is seborrhiec dermatitis in the scalp. This is due to an overgrowth of yeast named pityrosporum ovale. Some make sebum (oils) especially pref... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 44-year-old male asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Physical blocks: Depending on which neutrogena sunscreen you reacted to, the most common sun screen allergen is oxybenzone and its derivatives. You can switch to a su... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 23-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Most cysts come from invagination of the skin surrounding a follicle. Some theorize that follicular injury is what causes cysts to form. Some people... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 40-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Painful: Laser treatment of warts is through it's high energy and burning mechanism. It also targets the blood vessels that feed the wart, thought to contribu... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 38-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Yes, but...: Tattoos are generally safe, but some people are allergic to the elements that are in the tattoo dyes. Unfortunately, when that happens, other than in... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 38-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Frequent rinsing: Pressure sores are perfect areas for bacteria to colonize, inhibiting wound healing. With each dressing change, which should be at least twice a day,... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 27-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Inherited: Psoriasis is an inherited inflammatory condition that waxes and wanes. Treatment is generally directed towards control of symptomatic flares. Althoug... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.2k viewsReviewed >2 years ago
A 34-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
See a doctor: There are many lesions that are brown and raised. Many raised brown spots are benign such as seborrheic keratosis and benign moles. However, some me... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 33-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Nothing abrasive: As long as the facial does not involve any microdermabrasion, glycolic or salicylic or other fruity enzyme acid peels. Anything potentially abrasive w... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 47-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Depends on severity: There is not a single best way to treat psoriasis. Mild psoriasis is generally treated with topical steroids and vitamin d derivatives. More severe ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.1k viewsReviewed >2 years ago
A 23-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Close monitoring: Dysplastic nevus syndrome is a condition in which the person has many (often 100's) atypical moles. With the syndrome, one has a higher risk of devel... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 34-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Inherited: Eczema is generally inherited. There is usually family history for eczema, asthma or hayfever, together we call atopy. These three conditions are es... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 40-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Skin allergy test: Before you use a dye product, you should follow the instructions in the package to do a allergy skin patch test. Apply a small amount of dye on your ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 40-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Yes: Yes, smoking not only cause wrinkles around your mouth, it causes wrinkles elsewhere on your face.
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 25-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Sometimes: Scars are physiological response to injuries of the skin. Scars come in different forms: red, raised, depigmented, thinned, pitted, stretch mark like... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 35-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Non-FDA skin creams: Cosmeceuticals generally refers to a class of creams containing non-fda controlled active ingredients that "reduces the appearance of ..." wrinkles, p... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 27-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Non-healing wounds: If you have a growth that is not healing, and tends to bleed on its own, you should definitely bring it to the attention of your dermatologist. For p... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.4k viewsReviewed >2 years ago
A 40-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Antimicrobial: Silvadene (silver sulfadiazine) cream is antimicrobial, keeping pressure sores from becoming infected. In addition, the emollient (cream or ointment)... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A 27-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
ABCDE's of mole chec: Atypical moles that resemble melanoma often has one or all of the following characteristics: a for asymmetry; b for irregular borders; c for lots of d... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.3k viewsReviewed >2 years ago
A member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
See a dermatologist: This requires a clinical exam. Most commonly, the tiny bumps between your nose and eyes are syringomas (sweat gland growths), sebaceous hyperplasia (... Read More
Created for people with ongoing healthcare needs but benefits everyone.
6.2k viewsReviewed >2 years ago
A female asked:
Dr. Karen Hananswered
Dermatology 25 years experience
No: Co2 laser resurfacing removes a layer of skin in a controlled fashion. In some cases, patients with extensive precancers can be treated with co2 lase... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.3k viewsReviewed >2 years ago
A 38-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
See your PCP: If you don't have a rash, and only the described symptoms above, there could be underlying systemic disorder causing your sensation, such as diabetes.... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.9k viewsReviewed >2 years ago
A 48-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
Allergy?: If you have been diligent with moisturizing your hands each time you wash, and your rash doesn't go away, you might have contact allergic dermatitis. ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.9k viewsReviewed >2 years ago
A 48-year-old member asked:
Dr. Karen Hananswered
Dermatology 25 years experience
See a dermatologist: Peeling skin on the feet can be fungus vs foot eczema vs psoriasis vs genetic vs other. Treatment depends on the diagnosis.
Created for people with ongoing healthcare needs but benefits everyone.
5.9k viewsReviewed >2 years ago
TestimonialsRecommendations and Thank you notes are endorsements given from patients or other doctors.
Recommendations and Thank you notes are endorsements given from patients or other doctors.
2
Recommendations
845
Thank you notes
HealthTap member
Mar 30, 2015
Dr. Han is an amazing doctor! #nationaldoctorsday2015 #virtualflower1
HealthTap member
Mar 31, 2015
Dr. Han is an amazing doctor! #nationaldoctorsday2015 #virtualflower1
HealthTap member
Thank you, your answer was very helpful! This is exactly my condition. Another doctor answered, but wanted more info on this in particular. Thanks!
HealthTap member
Thanks for your quick reply! Thank you for your feedback! It's embarrassing and frustrating, and I hate that I have to deal with it :(
HealthTap member
Thank you, your answer was very helpful! my problem started,when I was over 50 and nothing l do clears itn up for good. thanks
Education & Training
Medical/Graduate school
UC San Francisco School of Medicine, CA
Graduated 1996MD
Medical/Graduate school
Northwestern University Feinberg School of Medicine, IL
Graduated 1998MD
Residency
University of California, Los Angeles
Awards
Top Dermatologist , First Place, San Mateo County, CA - Winter
2013
HealthTap Founding Doctor
HealthTap ClubMD
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