Our Singapore-based dermatologists have a wide breadth of experience, having trained in renowned centres such as the Massachusetts General Hospital (United States), St John’s Institute of Dermatology (United Kingdom) and Australia. Our specialists keep up to date with the latest developments in medical dermatology and are opinion leaders and invited speakers in their respective subspecialties.
Acne vulgaris, commonly known as pimples, is a common condition in adolescents and teenagers. Contrary to popular belief, adults can also get acne, even into the 40s.
Acne often affects the face, chest, shoulders and back. It can appear as comedones (whiteheads and blackheads), red bumps, pustules (small pus-filled blisters), or large and painful cysts and nodules. These can result in unsightly scars.
The causes of acne include:
Inappropriate use of comedogenic cosmetic products, steroids, and certain medications can also give rise to acne-like rashes.
Treatment for acne should be started early, as inflamed spots eventually give rise to scars that are more difficult and costly to treat. Mild acne can be treated with creams that contain retinoids (vitamin A derivatives), antibiotics, benzoyl peroxide, azelaic acid, etc. More severe acne should be treated with oral medications such as antibiotics, retinoids (isotretinoin) or hormonal therapy. Stubborn comedones can be extracted. Large and painful cysts can sometimes be injected with steroids to reduce inflammation or surgically removed. Chemical peels, photodynamic therapy and light-based treatments can also be used.
Once the active phase of acne is under control, treatment shifts to a maintenance regimen to keep acne under control, and acne scar treatment can be instituted.
Treatment for acne scar depends on the types of scar and the individual's skin type. Acne scars and treatments can classified as:
Allergy is an abnormal reaction to an ordinarily harmless substance. Many allergic reactions present as rashes on the skin, and dermatologists are often called to evaluate suspected allergies. Skin allergies can present in many forms. These can include itchy, red, blotchy and swollen patches (hives or urticaria), red, dry and scaly skin (eczema), or even painful blisters and ulcers (Stevens-Johnson Syndrome). Common allergens (triggers of allergy) include medications, foods, chemicals that get in contact with the skin (cosmetic products, hair dye, metals in jewelry), airborne substances and plants. Severe allergies can be dangerous. Early and accurate diagnosis with timely treatment is essential.
An accurate account of how the allergic reaction arose and identification of the type of skin reaction are the most important components in making the right diagnosis. This can be supported by specific tests to identify the allergen:
Treatment of allergies depend on the type of reaction, and can include creams and oral medications. Identification and removal of the allergen can prevent recurrences.
Dandruff, also known as seborrhoeic dermatitis or pityriasis capitis, is a common problem that causes itch, redness and flakiness on the scalp. Sometimes, the rash can extend onto the face, ears, and even the body. In infants, it can present as cradle scalp. The cause of seborrhoeic dermatitis is suspected to be due to a type of yeast called Malassezia that resides on human skin.
Treatment for seborrhoeic dermatitis includes shampoos that have anti-fungal or anti-inflammatory properties, and topical steroid or non-steroidal creams and lotions. Severe cases may require oral anti-fungal therapy.
Eczema (dermatitis) is one of the most common skin problems. It usually presents as intensely itchy, red, flaky skin. When eczema flares, patients may notice the rash becoming weepy and crusted. Gradually, the skin may become dry, scaly and thickened. Skin is eczema is also prone to secondary infection by bacteria or viruses.
There are many forms of eczema:
Most forms of eczema are diagnosed clinically and do not require any tests. Some tests we offer include:
Management of eczema requires a multi-pronged approach. Our doctors will usually take time to discuss the options with the patient, and reach a mutually acceptable form of treatment. Treatments that we offer include:
Hair loss is also known as alopecia. For normal people, it is common to shed 50 - 100 strands of hair a day. Excessive hair loss can be due to many causes. Hair loss can occur in localized patches, diffusely from the whole scalp, or in certain patterns.
This is a form of localized hair loss. Patients may notice circular, disc-shaped patches of hair loss on the scalp or other hair-bearing areas of the body. There is often no symptom such as itch or redness. Alopecia areata results from one's immune system reacting against one's own hair follicles. Treatment includes topical lotions, injections, immunotherapy and oral medications. Some of the latest treatments include Jak/Stat inhibitors (eg. tofacitinib or "Xejianz") which has been useful in patients with more severe disease.
This is a form of patterned hair loss, and is very common in both men and women. Male pattern hair loss usually presents with balding over the top of the head and receding hair line. Female pattern hair loss typically shows loss of hair over the crown of the head. There is tendency for androgenetic alopecia to run in families. Treatment depends on the severity of the condition and expectations of the patient. Options include topical lotions (eg. minoxidil), oral medications (eg. finasteride, minoxidil) and hair transplantation.
Telogen effluvium is a form of diffuse hair loss. Patients usually notice increased hair shedding during combing, after a shower, or on the pillow in the morning. Telogen effluvium is triggered by stress to the body. Stressful events include childbirth, severe illness, hospitalization, rapid weight loss, hormonal imbalance and certain medications. Most patients will recover spontaneously. Treatment may help to hasten recovery.
The medical term for hives is "urticaria". Urticaria is a very common skin problem, and it is likely that most people will have experienced hives at least once in their lives. Hives present as intensely itchy, red and swollen wheals on the body. Sometimes, they may cause swelling around the eyes or on the lips (angioedema). Urticaria may be classified as acute or chronic, depending on the duration of symptoms.
Treatment of urticaria includes a comprehensive analysis of possible allergens such as foods, medications, and other triggers including infections or physical stimuli. Avoidance of any trigger can bring significant improvement to the symptoms.
Many patients' urticaria can be satisfactorily treated with antihistamines. The dose of antihistamine required may be higher than the usual dose one can obtain from the pharmacy, and our specialists at TSN Dermatology will be able to guide you on how to adjust your dose to gain control of your urticaria.
In cases where the urticaria is more severe, treatment can also include short courses of steroids, cyclosporine, or omalizumab (Xolair). Omalizumab belongs to a class of medications called biologics, which are targeted therapies that often combine high efficacy and safety in most patients.
Keloids are thick scars that form as a result of excessive collagen deposition. It is an abnormal form of scarring. Keloids can develop after various types of injuries including accidents, burns, surgery, piercings, tattoos and acne. They may be itchy, painful or grow in size. Some people may be genetically prone to this form of abnormal scar formation.
Treatment for keloid scars depends on the size, thickness and location of the scar.
Ingrown nail occurs when the nail grows deeply into the flesh on either side, causing pain, swelling and sometimes discharge of pus. Ingrown nail can be a result of abnormal nail shape or overgrowth of the flesh beside it. Mild cases may be treated with warm soaks and ointments, with antibiotics for any secondary infection. Severe cases may benefit from surgery. Oftentimes, only part of the nail needs to be removed, which is much less painful than a complete nail avulsion (removal of the whole nail).
Melanonychia refers to brown or black pigmentation of the nail. The nail can be diffusely coloured, or present with a dark band running down the nail. Blood, melanin pigment or fungus can cause this pigmentation. Some medications or underlying illness can also trigger nail discolouration.
Melanonychia striata refers to a brown, black or grey longitudinal band running from the nail fold to the edge of the nail. In people with darker complexions (eg. Asians), this can occur on multiple fingers and toes, and is a benign condition. Melanonychia striata can also occur after injury to the nail. More rarely, it can be a feature of melanoma, an aggressive form of skin cancer. Melanonychia should be examined by a dermatologist using a special equipment called a dermatoscope, which can highlight any suspicious features.
Fungal infection can cause white spots to appear on the surface of the nail, thickening of the nail, separation of the nail from the flesh beneath, or for the nail to become crumbly. Fungal infections can sometimes be confirmed by sending samples of the nail for examination under the microscope, or attempts to culture the fungus.
Fungal nail infections often do not respond to creams or lotions, and will need oral anti-fungal medications, taken for 6 to 12 weeks or longer.
Digital myxoid pseudocyst usually appears as a small, dome shaped growth near the furthest joint of the finger. It can be skin-coloured, red, or pearly translucent in appearance. A clear, gel-like substance can be seen if the growth is pricked or burst. Digital myxoid pseudocysts are believed to come about from degeneration of the finger joint. They can be treated by repeated pricking and pressure, needle aspiration of the contents followed by injection of medication, or a minor surgery.
Psoriasis is a common, inflammatory skin condition that affects around 1 - 2% of people around the world. Patients with psoriasis often develop red, thick and flaky patches on the scalp, elbows, knees, lower back and buttocks. In some cases, the nails may become misshapen-ed. Around 10% of patients may develop psoriatic arthritis, giving rise to joint pain, swelling and deformity. Many people develop psoriasis in their 20s or 50s, though it can occur at any age.
In psoriasis, the immune system in the skin becomes more active, giving rise to inflammation. This inflammation causes the skin to become red, grow more quickly and become thicker. Genetics is the main reason why some people develop psoriasis, and more than 30 genes have been found to be associated with psoriasis. The environment also plays a role, with factors such as stress, bacterial infections, certain medications and trauma to the skin being able to trigger psoriasis.
Psoriasis is not a contagious condition. One cannot "catch" psoriasis from another person by touch, sharing food, or from common spaces such as the swimming pool.
Psoriasis is a genetic condition that is controlled by multiple genes. Whether a child develops psoriasis or not depends on the combination of all these genes that he or she inherits from both parents. The environment the child grows up in may also affect whether these genes become active or not.
Hence, although psoriasis is genetic disorder, most children having one parent with psoriasis will not develop psoriasis. Most patients with psoriasis also do not have an affected family member.
Treatment for psoriasis has improved significantly in the past 20 years. Although there is no "genetic" cure that can alter the psoriasis genes permanently, many patients can get very good response with some of the latest therapies available.
Doctors at TSN Dermatology are specialized and experienced in the use of the newest biologics in psoriasis treatment, including risankizumab (Skyrizi), guselkumab (Tremfya), ixekizumab (Taltz) and secukinumab (Cosentyx).
Rosacea is a chronic, inflammatory skin problem that causes the skin on the face to feel sensitive, flush easily, or develop red pimple-like spots. Patients with rosacea may notice their face turning red more easily in the sun, or after taking alcohol, or hot, spicy foods. As the disease progresses, the redness may become more persistent. Some patients may also develop swelling on the face, enlargement of the nose, or eye symptoms (ocular rosacea).
Rosacea can sometimes be mistaken for pimples (acne vulgaris). Unlike acne, rosacea usually does not have comedones (whiteheads or blackheads) and patients are slightly older.
Both genetics and the environment play a role in why some people develop rosacea. Blood vessels in patients with rosacea seem to be more sensitive to stimuli, giving rise to increased flushing. There also appears to be higher levels of chemicals that cause inflammation, deficiencies in the skin barrier (giving rise to dryness of the skin), and higher levels of Dermodex mites on the skin.
Treatment for rosacea depends on the main symptoms the patient is experiencing and the severity. The options include:
Cysts are benign growths that can occur anywhere on the body. They usually appear as smooth, dome-shaped, soft to firm lumps underneath the surface of the skin. Some cysts may have an opening on the surface that look like a comedo (blackhead). Various forms include epidermal (sebaceous) cysts, trichilemmal cysts, steatocystoma, milia cysts, etc.
Cysts contain fluid or semi-fluid material. Sometimes, this fluid can be expressed through the opening on the surface, and appear as a yellow to white, malodourous fluid.
Cysts may be left alone if they do not cause any trouble. They should not be squeezed, as this may cause the cyst to rupture and become inflamed. Cysts that are large, unsightly, or cause repeated inflammation should be removed by surgery. This usually involves a small cut on the surface of the cyst under local anaesthesia, and can be performed in the clinic.
Lipomas are benign growths composed of fat cells. These can occur anywhere on the body, be small or large in size, and singular or multiple. Lipomas often feel soft and mobile, and lie deep underneath the surface of the skin.
Lipomas may be left alone if they do not cause any trouble. If treatment is desired, they can be removed by a small cut on the surface of the skin. This is a minor surgery performed under local anaesthesia in the clinic. If a lipoma starts to grow or become painful, one should see a doctor and have a biopsy, to make sure the lump is not a liposarcoma, which is a rare but dangerous type of cancer.
Sebaceous hyperplasia are enlargement of oil (sebaceous) glands on the face. They become more common with age. Sebaceous hyperplasia may be removed by a minor procedure under topical anaesthesia, such as electrocautery or laser.
Seborrhoeic keratoses are common, brown to black growths that are more commonly seen in people above the age of 40. They can range from a few millimeters to few centimetres in size, and often have a rough or waxy surface. Large seborrhoeic keratoses may become irritated or inflamed when they are caught or rub against clothes. These growths can be treated by cryotherapy, or a minor surgery such as electrocautery or laser.
Skin tags are soft, skin coloured growths that usually appear on the neck, armpits, groins and inner thighs. They usually have a narrow stalk attaching them to the skin. Skin tags, especially large ones, may get irritated or "strangulated" when they are caught on clothes. They can be removed by minor surgery under topical anaesthesia or by laser.
Skin cancers are abnormal growths on the skin. They are the most common type of cancer worldwide, and rank amongst the ten most common cancers in Singapore. Most skin cancers arise due to exposure to ultraviolet radiation in sunlight. Skin cancers are more frequently seen in older people and on sun exposed areas, although they can occur in younger people and covered areas.
The most common skin cancers are basal cell carcinoma, squamous cell carcinoma and melanoma. Diagnosis of skin cancers is aided by dermatoscopy, a specialized tool often used by dermatologists. Patients at risk for skin cancers (eg. those of fair complexion, history of repeated sun exposure, weak immunity, previous skin cancer) should see a dermatologist regularly for total body skin monitoring.
A skin cancer screen or mole check is a thorough skin examination by a specialist. This can sometimes take more than 30 minutes. A dermatologist will usually use a dermatoscope, a specialized tool that helps to identify unique patterns under the skin, to help make a more accurate diagnosis.
Our method at TSN Dermatology usually starts with taking a comprehensive history, to identify the risk level a patient has for skin cancer. This is followed by examination, firstly of the growths that the patient is worried about, and then the rest of the skin from head to toe. We aim to be thorough, but will protect your modesty and make you comfortable at all times.
If any suspicious growth is identified, our doctor will discuss with you the options available, ranging from close observation of the growth to taking a skin biopsy. The consultation ends with education on how to perform self-monitoring of the skin and sun protection. Regular skin checks by the doctor should be performed every 6 to 12 months.
Basal cell carcinoma account for 70 - 80% of all skin cancers. They present as skin-coloured or slightly reddish growths or ulcers on the skin. Basal cell carcinomas are generally fairly slow growing. Patients may notice that the lump has been present for some time, but more recently started to bleed with minor trauma eg. when wiping the face with a towel. Basal cell carcinomas rarely metastasize (spread beyond their local area of growth). Treatment is often by surgery, especially Mohs Micrographic Surgery which offers the highest cure rates and smaller wounds than standard surgery. Other options include radiation therapy, cryotherapy and topical creams.
Squamous cell carcinoma make up around 20% of all skin cancers. They usually appear as reddish, rough bumps on skin that has been chronically exposed to sunlight. The lump may sometimes break down to form an ulcer on the surface. Common areas where squamous cell carcinomas arise include the scalp (for men with sparse hair), face, arms and back of the hands. This type of cancer can sometimes spread to the lymph nodes or other parts of the body. Treatment is usually by surgery; radiation therapy is also an option.
Melanomas are a less common, but highly aggressive form of skin cancer. They arise from melanocytes (pigment cells) in the skin, and hence often mimic normal moles. Melanomas have a risk of spreading to the lymph nodes and other organs, and so need to be diagnosed and treated early. Use of dermatoscopy, a specialized equipment that magnifies the appearance of tissue underneath the skin surface, can help make diagnosis of melanomas more accurate. Early melanomas are often treated by surgery alone. Advanced stage melanomas may require more extensive surgery such as removal of lymph nodes and immunotherapy.
Actinic keratoses are pre-cancerous growths that often appear on skin that has been exposed to the sun for a long time. They often appear as red, rough patches on the scalp (in men with sparse hair), face, arms, back of the hands and legs. Actinic keratoses are at risk of progressing to become squamous cell carcinomas, and should be treated. Treatment includes cryotherapy and topical creams.
Pityriasis versicolor is a common cause of "white spots" in young adults. It can appear as white, light brown and red flaky patches on the body and limbs. The rash can be slightly itchy, especially after sweating.
Pityriasis versicolor is caused by a yeast called Malassezia. The fungus produces a chemical that causes the skin to lose its colour temporarily. Treatment is with anti-fungal washes, creams or oral anti-fungal tablets in severe cases. The white patches may take weeks or even months to recover its colour.
Ringworm is caused by fungus infecting the skin. It appears as a red, flaky ring that grows outwards and can be quite itchy. Ringworm often affects warm and moist areas such as the groin (tinea cruris; jock itch), feet (tinea pedis; athlete's foot) and body (tinea corporis). It can also affect the scalp (tinea capitis), causing patches of hair loss, and the nails (tinea unguium), resulting in discolouration and destruction of the nail.
Ringworm can often be treated with anti-fungal creams. Oral medications may be needed if the infection is extensive or when nails are affected.
Viral warts are common viral infections, caused by the Human Papillomavirus (HPV). They can appear as thickening of the skin with many tiny black dots on the palms and soles, or as small rough spots on other parts of the body. One should avoid scratching or picking the warts, as this may allow the virus to spread.
Treatment of viral warts include topical lotions (which can be applied by the patient or the doctor), cryotherapy (liquid nitrogen freezing), electrocautery, immunotherapy and laser.
Shingles is a painful, blistering rash that can appear on the face, body or limbs. Patients may initially feel pain, tingling or some unusual sensation on the skin before the blisters appear. The blisters often contain blood-tinged fluid and are distributed in a band. The blisters often dry and scab over in a couple of weeks. Some patients may have residual neuralgic (nerve-related) pain that can last for months or even years.
Shingles is caused by reactivation of the Varicella Zoster virus, the same virus that causes chickenpox. After one has recovered from chickenpox infection, the Varicella Zoster virus lies dormant in the nerves in the body. After many years, when one's immunity to the virus has waned, the virus may reactivate, giving rise to shingles. Shingles can be precipitated by stressful events.
Treatment using oral anti-viral medication is most effective when administered early. This can reduce the number of blisters formed and the duration of blistering. This translates to smaller scars and less risk of secondary infection by bacteria. A vaccine for shingles is available.
Molluscum contagiosum is a viral infection more commonly seen in young children. It causes white or pink, smooth, dome-shaped bumps to appear on the skin.
Molluscum is caused by a Poxvirus, and can spread from person to person. Treatment includes topical creams, minor extraction under topical anaesthesia, cryotherapy or laser.
Abscesses are collections of pus within the skin. They appear as painful, warm and red swellings. Sometimes, the yellowish pus underneath can be visible. Abscesses are caused by bacterial infection. Bacteria can enter the skin either through small cuts on the skin, or via hair follicles (and hence appear on hair-bearing areas such as the armpits or groin).
Abscesses should be treated with antibiotics and surgical drainage to release the pus. The wound will need to be dressed regularly until it heals.
Erysipelas and cellulitis are bacterial infections of the skin. They appear as painful, warm, swollen red patches, and are often accompanied by fever. A commonly affected area is the leg, where it can cause severe pain and difficulty with walking.
The common causes of erysipelas and cellulitis are bacteria called Staphylococcus and Streptococcus. People with reduced immunity (such as those with diabetes) or poor circulation of the legs are at higher risk. Patients should be treated with oral or intravenous (injection) antibiotics and encouraged to rest or elevate their legs (if the infection occurs on the leg).
Warts or verrucae are viral infections caused by the Human Papillomavirus. On the palms and soles, they can appear as painful thickened growths on the palms and soles, often with small black dots on the surface. On the rest of the skin, warts can look like skin coloured or brown bumps with a rough surface. Warts are spread by physical contact. At the genital area, they can be sexually transmitted.
Treatment for viral warts includes topical lotions (which can be self-administered or administered by the doctor), cryotherapy (freeze therapy), immunotherapy. surgery, electrocautery or laser.
Our specialists provide a comprehensive range of dermatological treatments, personalized to suit your unique requirements.
Aesthetic dermatology is focused on restoring beauty to the skin, recreating a youthful appearance, and ultimately helping our patients feel happier and more confident in their own skin. At TSN Dermatology, we believe in listening empathetically to your concerns, and providing sincere recommendations on how to help you achieve a healthier look. We employ both […]
Dr Koh Hong Yi is a qualified dermatologic and Mohs micrographic surgeon. He was trained in Ninewells Hospital, Dundee, which is one of the largest Mohs surgery centre in the UK. Dr Koh established the Mohs micrographic surgery service at Singapore General Hospital (SGH). He currently performs Mohs surgery in his private practice, and also […]