Jonathan Guinto graduated from Seton Hall University’s 6-year dual degree physician assistant program with a Bachelor of Science in biology and a Master of Science in physician assistant studies. It was during his medical training in the New Jersey/New York City area, where he felt a natural draw to dermatology. He demonstrated clinical excellence with his strong visual memory along with his gentle and steady approach to performing procedures. After graduation, he furthered his knowledge in dermatology by completing the rigorous and lengthy Society of Dermatology Physician Assistants (SDPA) Diplomate Fellowship™️ which is the premier training program for physician assistants in the field of dermatology.
Prior to joining U.S. Dermatology Partners, Jonathan provided excellent dermatologic care for patients of all ages in multiple clinic settings and skilled nursing facilities across Southern California. His combination of outstanding medical training, history of superb patient satisfaction, and continued pursuit of dermatology excellence makes him a great addition to our team. His organized and thorough approach to dermatology allows him to actively listen to his patient’s concerns while providing the highest quality care possible. Jonathan always strives to pick the best, safest, & most cost-effective treatment plans for his patients of all ages.
In his free time, Jonathan enjoys watching stand-up comedy, going out to the movie theatre, golfing (with sunscreen on), and listening to podcasts and audiobooks.
Actinic Keratosis, also known as solar keratosis, is a scaly or crusty lesion on the skin that develops slowly and indicates the presence of sun damage. It is most commonly found on parts of the body frequently exposed to the sun including the bald scalp, face, ears, lips, backs of the hands or forearms, neck, and shoulders.
Actinic keratoses are considered precancerous and can develop into a type of skin cancer called squamous cell carcinoma. In fact, some 40 to 60 percent of squamous cell skin cancers begin as untreated actinic keratoses.
Because of this, your doctor should be diligent in diagnosing, treating and monitoring actinic keratosis.
Annual Skin Examinations are yearly scheduled skin exams with a dermatologist. Did you know that skin cancer is the most common form of cancer in the U.S.? In fact, it is estimated that one in five Americans will develop skin cancer in their lifetime. Sun damage to the skin is cumulative over a person’s lifetime, so the average risk of skin cancer also increases as our life expectancy gets longer.
Just as you schedule your annual physical or trip to the dentist, it is important to conduct a self-examination of your skin each month and schedule a professional annual skin examination once a year. Skin cancer is a treatable condition, but early detection is key.
Basal Cell Carcinoma, also known as basalioma or basal cell cancer, is the most common type of skin cancer and carries the least amount of risk, though it still requires attention. If caught and treated early, basal cell carcinomas are not likely to be life-threatening, but they do have the potential to cause disfigurement of the skin tissue.
Almost one million new cases of basal cell carcinoma are diagnosed each year in the U.S., and up to 30% of Caucasians may develop basal cell carcinomas in their lifetime.
Skin cancer is considered low risk when the affected cells remain clustered in a single group. Both basal cell carcinoma and squamous cell carcinoma are rarely life-threatening. Though it is unlikely to spread to other parts of your body, if left untreated, basal cell carcinoma can move into nearby bone or other tissue.
Basal cell carcinoma typically begins as a small, shiny bump on the face, although it can occur on any part of the body.
Cryotherapy, or “cryosurgery,” is a simple, non-invasive procedure in which liquid nitrogen is used to freeze and destroy growths on the surface of the skin. This is an effective treatment for precancerous skin lesions (actinic keratoses), as well as other skin conditions such as warts, skin tags and moles.
Applying liquid nitrogen to skin lesions allows dermatologists to target the damaged skin cells and destroy them at the cellular level. After freezing, the affected area may blister and scab over, and should heal within three to six weeks.
Our dermatology team uses cryosurgery to treat a wide range of conditions. It offers a number of advantages: Cryotherapy is a simple, affordable outpatient procedure, the discomfort level is minimal, and there is a low risk of infection.
Melanoma, the deadliest of skin cancers, only accounts for about 4 percent of all skin cancer cases, but causes about 79 percent of skin cancer deaths.
Melanoma is a cancer of the skin that begins in the melanocytes, which are the cells that produce the pigment melanin. It is the leading cause of cancer death in women 25 to 30 years old and the second leading cause of cancer death in women 30 to 35 years old.
In some cases, melanoma occurs in melanocytes throughout the body, even if those parts have never been exposed to the sun.
A rare and aggressive form of skin cancer, sebaceous carcinoma is sometimes referred to as sebaceous gland carcinoma, sebaceous gland adenocarcinoma or meibomian gland carcinoma.
Sebaceous carcinoma can develop in any sebaceous glands, which lubricate the skin, but it most often begins on or around the eyelids. If it is found and treated early, treatment is often successful. However, if sebaceous carcinoma spreads, it can be deadly.
Because sebaceous carcinoma can appear to be a benign growth such as a stye, diagnosis is often delayed, which increases the risk of death. If you notice a growth on your eyelid, it’s important to make an appointment with your dermatologist. The sooner sebaceous carcinoma is diagnosed and treated, the better the outcome.
Skin cancer is the most common form of cancer in the U.S. with more than 3.5 million cases diagnosed each year.
Skin cancer is the result of uncontrolled growth of abnormal skin cells that takes place when skin cells suffer DNA damage and then mutate, causing them to multiply rapidly and form malignant (cancerous) tumors. Most skin cancers develop on the visible outer layer of the skin (the epidermis), particularly on sun-exposed areas such as the face, head, hands, arms and legs. They are usually easy to detect with a skin examination, which increases the chances of early diagnosis.
There are different types of skin cancer, each named for the type of skin cell from which they originate. The most common type of skin cancer is basal cell carcinoma. Almost one million new cases of basal cell carcinoma are diagnosed each year in the U.S. Most skin cancers fall into one of three categories:
There are often warning signs that cancer is developing. The most common are pre-cancerous lesions called actinic keratoses that often develop on sun-exposed areas. These tumors replace normal surrounding tissue and generally do not spread to other areas.
Skin cancer is considered low risk when the affected cells remain clustered in a single group. Both basal cell carcinoma and squamous cell carcinoma are rarely life-threatening.
Skin cancer is considered a high risk when cells have invaded surrounding tissues. The third most common skin cancer, malignant melanoma, can be life-threatening if not diagnosed and treated early.
If skin cancer is detected before it has spread to surrounding tissues, the chances of a complete recovery and cure are excellent. High-risk forms of cancer like melanoma require more aggressive treatments.
Squamous Cell Carcinoma is a common form of skin cancer that develops in the squamous cells that make up the outer layer of the skin. Although it is usually not life-threatening, it can be aggressive in some cases.
If left untreated, squamous cell carcinoma can grow large or spread to other parts of your body, causing serious complications.
Acanthosis Nigricans is a condition that causes the skin to become discolored in the creases and folds of your body. This dark colored skin sometimes becomes thickened and often shows up in the armpits, groin and the folds of the neck.
Acne is a dermatological condition caused by inflammation and mild infection in clogged pores. If not properly treated, acne can cause emotional distress, low self-esteem, and depression. In severe cases, it can even lead to permanent scarring.
While not a serious physical health threat, acne is an embarrassing skin problem that can be life-altering for many patients. Though it is most common among teenagers, acne can affect anyone, regardless of age or gender, and can be mild, moderate or severe.
A dermatologist may recommend allergy patch testing to pinpoint the sources of allergic skin response. These tests can help you to avoid allergens and improve your skin and overall health. You can learn more about allergy patch testing at U.S. Dermatology Partners on this page or by contacting the location nearest you to schedule a consultation with one of our knowledgeable dermatologists.
Alopecia Areata, also known as spot baldness, is a type of hair loss in which your immune system attacks hair follicles. This leads to areas of baldness on the scalp and body. In severe cases, a person with alopecia may even lose the hair of their eyebrows and eyelashes.
Athlete’s Foot earned its name because this contagious fungal infection is commonly seen in athletes, who may wear sweaty socks for long periods of activity. It affects the skin on the feet and, left untreated, can spread to toenails and even to your hands.
Related: 5 Common Foot Rashes
If you’ve noticed new skin growths, lumps, or bumps, chances are you’re dealing with a lesion. But, to know whether or not the lesion is benign, you’ll need to consult with a professional. At U.S. Dermatology Partners, our skilled dermatologists can partner with you to determine the type of lesion and help you decide if treatment is necessary for your condition. To get started, simply fill out our online scheduling request form, and a U.S. Dermatology Partners team member will be in touch to finalize the details of your visit.
Benign lesion is an umbrella term that may reference any number of non-cancerous lesions of the skin. These lesions may develop on any part of the body with soft tissue. They are classified (named) according to their specific sets of features, where they develop, and other characteristics. Determining if a lesion is non-cancerous requires an accurate diagnosis from a dermatologist.
Cold sores, which are also called fever blisters, are groups of blisters that appear on the lip and around the mouth. The blisters may break open and leak a clear fluid and then scab over. They may take up to two weeks to heal. They are caused by the herpes (HSV) virus.
Contact dermatitis is a common skin condition that impacts millions of people. At U.S. Dermatology Partners, we can help patients who struggle with contact dermatitis and other skin conditions to address their symptoms and look and feel their best. You can learn more about contact dermatitis on this page or by scheduling a consultation with a U.S. Dermatology Partners office location in your area.
Cysts are pockets of tissue (sacs) that may become filled with pus, fluids, skin cells, and even air.
They are fairly common on the skin and can appear anywhere on the body. Cysts may feel like a pea under the surface of the skin, but without removal, they can grow significantly larger over time. In most cases, cysts are not painful, and they grow slowly. There are different types of cysts as we’ll discuss in the next section, and the vast majority of these skin growths are benign (not cancerous). Not all cysts will require treatment, but it is vitally important to have any lump under the skin evaluated and diagnosed by a board-certified dermatologist because some soft tissue malignancies (growths that are cancerous) can present like a cyst. Before recommending removal or other cyst treatments, your dermatologist will examine the growth to determine whether it is likely to cause you pain, become infected, or otherwise lead to skin health issues.
Dandruff is a condition of the scalp which causes flaking and itching of the skin. It is more common in people with the skin conditions seborrheic dermatitis, psoriasis and eczema, and also can be a reaction to hair or skin products.
Dermatitis, also sometimes referred to as eczema, is a common condition characterized by an itchy rash and inflamed skin. There are many different types of dermatitis and symptoms can range in severity from mild itching and redness to severe blistering and cracked skin.
Eczema, also sometimes referred to as dermatitis, is a common condition characterized by a certain type of inflammation in the skin. There are many different types of eczema and symptoms can range from mild itching and redness to severe blistering and cracked skin. Whether you’re newly diagnosed with eczema or you’ve struggled with this chronic skin condition for years, you know that finding a treatment that works for you isn’t just important – it’s essential. Without proper and effective interventions, people with eczema can experience significant discomfort, itching, and inflammation.
At U.S. Dermatology Partners, our knowledgeable dermatologists partner with their patients to develop and maintain an effective eczema maintenance plan and provide advanced treatments for serious flareups. Learn more on this page or contact U.S. Dermatology Partners to get started working with us today.
A fungal infection is an inflammatory condition that is caused by fungus. Fungal infections can appear in many parts of the body and include athlete’s foot, yeast infections, skin and nail infections and more.
Related: 5 Common Foot Rashes
You might ask, what does hair loss have to do with skin?
Hair is actually a protein filament that grows from follicles deep in the skin up through the top layer of your skin. Your hair helps to regulate body temperature and also serves to protect your scalp. Almost everyone experiences some degree of hair loss at some point in life.
Head lice is a common condition, especially among children. While it may sound creepy or embarrassing to have small mites (or nits) in your hair, it’s actually a very manageable condition that is typically easy to treat right at home. On this page, you can learn more about how to get rid of lice from your head and your home.
Herpes simplex virus, often referred to simply as HSV, is an extremely common viral infection impacting millions of people in the U.S. alone. While there’s no known cure for HSV, some treatments have proven effective in minimizing the number and severity of flare-ups. You can learn more about HSV, its symptoms, and treatment options on this page. You can also work with one of the knowledgeable professionals at U.S. Dermatology Partners to create a treatment plan. To get started, simply complete our online scheduling request form. One of our team members will be in touch soon to finalize the details of your treatment plan.
Hidradenitis suppurativa is rare skin condition in which small, painful lumps develop under the skin, usually in areas where the skin rubs together (armpits, groin, between the buttocks, under the breasts, etc.) or in areas near hair follicles where many oil and sweat glands are present. Sometimes, the lumps may break open and smell, or they may create tunnels under the skin.
It can continue for many years, may worsen over time and can have serious effects on your daily life and emotional well-being, particularly during outbreaks.
If you’re dealing with the itchy, inflamed, painful skin condition called hives, it may be time to call U.S. Dermatology Partners for help. Hives can be very uncomfortable, but recognizing the warning signs and taking appropriate actions to care for your skin can be important to quickly relieve these symptoms and get back to feeling your best. Keep reading to learn more about what causes hives and how your dermatologist can treat this condition.
Hyperhidrosis, often referred to as excessive sweating, occurs when people experience disproportionate and/or unnecessary sweat production. While sweating is a natural function of the body’s systems to keep itself cool and maintain the best temperature, sweating too much or sweating that is not necessary to cool the body can create many difficulties that impact your overall health and wellbeing. Generalized hyperhidrosis may affect the whole body. Others have localized cases of excessive sweating that impact only certain areas. Specifically, there are three main types of localized hyperhidrosis: axillary (impacting the underarms), palmar (impacting the palms), and plantar (impacting the feet). If you experience general or localized excessive sweating at least once per week, you should talk to a dermatologist about a treatment plan.
Melasma is a fairly common skin condition that creates the appearance of brown to gray-brown patches of skin, usually on the face. It can also occur on the neck and forearms and is the result of the body producing too much melanin, that natural substance that colors our hair, skin, and eyes.
If you’re dealing with dark spots or patches on your skin from the chronic condition melasma, the U.S. Dermatology Partners team can help you to improve the appearance of these spots and minimize the risk for future flare-ups of the condition. Read the page below to learn more or reach out to the U.S. Dermatology Partners location nearest you for more information.
Atypical moles, also known as dysplastic nevi, are unusual-looking benign (noncancerous) moles.
A dysplastic mole is one that, when viewed on a cellular level, has features unlike those of a healthy, benign mole. A benign mole will have a regular pattern of coloration and pigment, even borders, symmetry, and a tan or pink color. Dysplastic moles can be asymmetric, have indistinct borders, or contain multiple colors or very dark pigment.
Dysplastic moles are often spotted as the “ugly duckling” on a patient’s skin. Any departure from the typical mole a person’s skin makes may be dysplastic. They can appear anywhere on the body, but in most cases are found on the back, chest, buttocks, breasts, or scalp.
Molluscum contagiosum is a contagious skin disease that appears as pink or flesh-colored bumps on the skin. It is caused by skin-to-skin contact as well as from sharing towels, clothing or touching infected surfaces. It can also be acquired through sexual contact.
For adults, bumps are most often found on the face, neck, armpits, arms and hands. They may also appear on the genitals, abdomen and inner thighs.
Once you are infected with the virus, it can spread to other parts the body, especially if you pick or scratch at the bumps or touch other parts of your skin after touching the bumps. (This is called self-re-infection.)
A fungal infection of the toenails or fingernails typically looks like white or yellowed nails that may also be thick and brittle. The infection could affect one nail or part of a nail, or it could affect multiple nails. If left untreated, fungal infections can lead to permanent nail damage.
Telemedicine, also known as online dermatology, telehealth, or teledermatology, is the use of telecommunications technology to provide care across a distance. This includes using the Internet, cell phones, SMS messaging and even satellites to allow physicians and patients to communicate medical information. This technology has been available for over a decade now, but as it has gotten better and better, telemedicine has now become much more available, easy to use, and secure. If used in the right way, it is one of the best ways that we can improve access to care.
Because dermatology is a very visual field and a specialty in high demand, patient access is often challenged by long wait times. Meeting a dermatologist online can be a great way to provide patients with increased access to skin care. Teledermatology involves the use of real-time video streaming, or more commonly the transmission of still images, pictures, and video in combination with a patient’s medical information collected via questionnaire. Teledermatology can be utilized in many ways including physician-to-physician consultations, triage, follow-up care, and patient education.
When your child develops a persistent rash or other skin condition, your goal is to find the appropriate treatment as quickly as possible to keep them comfortable and healthy. Pediatric dermatology is designed to meet the special needs of children with such conditions as birthmarks, psoriasis, warts, eczema and other skin disorders.
Psoriasis is a chronic autoimmune inflammatory condition that causes patches of skin to become red, inflamed, and bumpy. This disease affects more than 8 million people in the U.S.
Psoriasis occurs when the immune system mistakes skin cells for a virus or other infection and responds by producing more skin cell growth. This can be triggered by stress, anxiety, injuries to the skin, infections and hormonal changes.
Despite the name, ringworm is not caused by worms; it is a skin infection caused by a fungus. It can be caused by touching another person who has the infection, or by sharing items that the person has been in contact — such as towels, bedding, chairs and clothes. It can also be caught from animals with fungal infections and, rarely, from contact with fungi in the soil.
Rosacea is a fairly common skin condition that causes redness in your face. In some cases, it may also produce small, red, pus-filled bumps. Typically these signs and symptoms may flare up for a period of weeks to months and then diminish for a while.
Rosacea may sometimes be mistaken for acne, an allergic reaction or other skin problems. It is believed to be caused by a combination of hereditary and environmental factors.
Learn more: 4 Types of Rosacea
Sebaceous hyperplasia is a benign bump on the skin that forms as a result of over-productive oil glands. When oil glands are damaged, they can become enlarged and clogged, leading to this condition. It is primarily a cosmetic concern rather than a medical problem.
Seborrheic keratosis is one of the most common noncancerous skin growths found in older adults. It most commonly appears as a brown, black or light tan growth on the face, chest, shoulders or back. Although they are not cancerous, they can look like skin cancer.
Shingles, also known as herpes zoster, is a painful skin rash that occurs when the virus that causes chickenpox reactivates.
Typically, shingles appears on a small area on one side of the face or body. The rash is often painful because it travels up nerve roots (which supply sensation to your skin) to the area of skin supplied by those specific nerve roots.
Skin tags are small, soft skin growths that can occur anywhere on the body but are most common on the eyelids, neck, armpits, groin folds and under the breasts. They are harmless but they can be annoying, particularly if they are in an area where they are rubbed on by clothing. They may be flesh-colored, pink or may darken.
The sun can age and burn your skin, and it can also cause damage on the cellular level, leading to skin cancer. The good news is, the U.S. Dermatology Partners team can help you formulate a plan to prevent sun damage and repair the effects of the sun’s UV rays so that you can go out and enjoy a sunny day. Learn more on this page or contact U.S. Dermatology Partners to schedule an appointment with us.
Individuals who are prone to sunburn are thought to be genetically predisposed to skin cancer. Risk is also increased when exposure to UV rays is excessive. Sunscreen helps prevent the damaging effects of ultraviolet radiation, including skin aging and skin cancer like melanoma and squamous cell carcinoma.
Sunscreens are rated and labeled with a sun protection factor (SPF) that measures the fraction of sunburn-producing UV rays that reach the skin. The higher the SPF, the greater the protection.
Vitiligo is an autoimmune disease in which white patches of skin appear on different areas of the body. This happens when melanocytes, the cells that make pigment in the skin, are destroyed. In addition to the skin, it can affect the mucous membranes of the mouth and nose as well as the eyes. Its cause is not known.
Warts are benign, non-cancerous growths that appear on the skin as the result of a virus called human papillomavirus, or HPV. They are contagious and are spread by contact – either with the wart or something that touched the wart. Cut or damaged skin is more vulnerable to warts.
Related: How to Identify a Wart
Keloids are raised, red scars created by excessive healing of skin wounds, such as burns, cuts and acne. They are the result of an overproduction of collagen as the skin tries to repair itself. Keloids also can occur after piercings, tattoos or surgery and often times are itchy and painful. They can grow for years and sometimes show up three months or longer after the injury occurred.
Keratosis pilaris is a common skin condition characterized by small, hard bumps that may make your skin feel like sandpaper. Most often they appear on your upper arms, thighs and buttocks, and sometimes are accompanied by redness or swelling. In some cases they may appear on your face.
It is caused by a buildup of keratin, a protein that protects skin from infections. When a buildup forms, it blocks the opening of a hair follicle and creates the bumps, but doctors don’t know what triggers the buildup.
Latisse is a product designed to help grow eyelashes and has been on the market since earning FDA approval in December 2008. It is designed to help grow longer, lusher eyelashes and is available only by prescription.
Skin lightening is a process used for people who want to lighten certain areas of skin that are affected by such things as melasma, age spots or even freckles.