Self-Check for Skin Growths Before Summer Leisure: 80% Don't Perform It and Leave Them Untreated! 5 Signs to Watch Out For Revealed in Survey of 300 People Aged 20-50

【Conclusion】Key Points of This Survey

To summarize, the five skin signs to check before summer leisure are: "sudden increase in size," "change in color," "bleeding or discharge," "irregular borders," and "persistent itching or pain." It is recommended to perform a self-check once a month after bathing, by examining your entire body in a mirror. In particular, growths that are "6mm or larger," "asymmetrical," or have "uneven coloration" should not be left untreated; seek medical attention from a dermatologist promptly.

- 82.3% responded that they do not perform self-checks for skin growths before summer leisure.

- 67.7% have experience leaving "concerning skin growths" untreated.

- The top reason for leaving them untreated was "not knowing when to seek medical attention," at 54.2%.

Glossary

What are Skin Growths (Skin Tumors)?

Skin growths (skin tumors) are a general term for benign or malignant lumps that occur on the skin. This includes benign tumors such as moles, atheromas, lipomas, and warts, as well as malignant tumors like basal cell carcinoma, squamous cell carcinoma, and melanoma.

What is the ABCDE Rule?

The ABCDE rule is a self-check criterion for the early detection of melanoma. It is evaluated based on five items: Asymmetry, Border irregularity, Color variation, Diameter (6mm or larger), and Evolving (changes).

What is an Atheroma?

An atheroma is a benign tumor where a sac-like structure forms under the skin, accumulating keratin and sebum within it. If left untreated, it can become infected or inflamed, and complete removal requires surgical excision of the entire sac.

Comparison of Growths Requiring Attention vs. Those That Can Be Monitored

Check Item

Requires Attention (Prompt Medical Consultation Recommended)

Can Be Monitored

Change in Size

Rapidly increasing in size

No change over a long period

Coloration

Uneven color (black, blue, red, etc.)

Uniform color

Border

Irregular or unclear

Smooth and clear

Shape

Asymmetrical

Symmetrical

Bleeding/Discharge

Bleeding without being touched

None

Subjective Symptoms

Persistent itching or pain

Asymptomatic

*These are general guidelines and individual differences exist. If you have any concerning symptoms, do not self-diagnose; consult a medical institution specializing in dermatology.

IC Clinic (Shinjuku, Shibuya, Ueno, Ikebukuro, Tokyo, Omiya branches), operated by Medical Corporation Tetsukenkai, conducted an "Awareness Survey on Self-Checks for Skin Growths Before Summer Leisure" targeting 300 men and women aged 20-50 nationwide, in conjunction with "National Safety Day" on July 1st. We report the survey results on early detection points for skin problems that should not be overlooked, ahead of the peak summer season when opportunities to expose skin increase with activities like swimming, beach trips, and camping.

Survey Background

July 1st of each year is designated as "National Safety Day" to raise awareness about safety in daily life. The summer leisure season increases opportunities to expose skin, making it a time when "skin growths" on areas usually covered by clothing are more likely to be noticed. However, it is currently difficult for the general public to determine which "skin growths" should not be left untreated. Since early detection and treatment of skin cancer can significantly improve prognosis, this survey was conducted with the aim of clarifying the current state of self-checks before summer leisure and the factors hindering medical consultation, to facilitate appropriate awareness.

Survey Overview

Target Audience: Men and women aged 20-50 nationwide who plan to engage in summer leisure activities such as swimming, beach trips, and camping.

Survey Period: June 8-17, 2026

Survey Method: Internet survey

Number of Respondents: 300

Survey Results

Over 80% Do Not Perform Self-Checks for Skin Growths Before Leisure

Question: Before going on summer leisure activities (swimming, beach trips, camping, etc.), do you perform self-checks for "skin growths" on your body?

Combining "rarely check" and "never check," 82.3% responded affirmatively, indicating that those who have a habit of self-checking before summer leisure are a minority. Especially in summer, when skin exposure increases, it is important to check areas that are usually overlooked.

Approximately 70% Have Experience Leaving "Concerning Skin Growths" Untreated

Question: Have you ever been concerned about a "skin growth" on your body but left it untreated?

67.7% reported having experience leaving "concerning skin growths" untreated. This reveals that many people do not seek medical attention despite feeling something is wrong, suggesting the need for information that lowers the barrier to consultation.

Top Reason for Leaving Untreated is "Uncertainty About When to Seek Medical Attention" at 54.2%

Question: Please select the most applicable reason for leaving skin growths untreated. (Respondents with experience of leaving them untreated only)

The top reason for leaving them untreated was "not knowing how much of a problem it is to warrant medical attention," accounting for 54.2%, over half of the respondents. A lack of awareness about specific criteria for seeking medical advice is a major factor hindering early consultation.

Awareness of the "ABCDE Rule" is Only 8.7%

Question: Do you know how to distinguish between "dangerous skin growths"?

Only 8.7% knew about the "ABCDE rule," which is the criterion for early detection of melanoma. Half of the respondents answered "completely unaware," highlighting the urgent need for awareness campaigns on specific self-check methods.

"Bleeding" is the Strongest Trigger for Seeking Medical Attention

Question: What kind of change would prompt you to seek medical attention from a dermatologist? (Select one most important from multiple choices)

"Bleeding or discharge" was the most common response at 35.7%, followed by "sudden increase in size" at 27.3%. However, since there are cases where medical attention should be sought even before these symptoms appear, there is a need to increase awareness for seeking consultation at an earlier stage.

Survey Summary

This survey revealed that less than 20% of people perform self-checks for skin growths before summer leisure, and approximately 70% have experience leaving concerning growths untreated. The main reason for leaving them untreated is "not knowing when to seek medical attention," with a lack of awareness about specific consultation criteria hindering early detection. Furthermore, the awareness of the "ABCDE rule" is less than 10%, making awareness campaigns on self-check methods an urgent necessity. The summer leisure season is a good opportunity to check one's skin, and it is important to establish a habit of monthly self-checks and foster an awareness of seeking prompt dermatological consultation for any concerning changes.

Doctor's Comment | Dr. Kota Takakuwa, IC Clinic

Based on over 15 years of clinical experience as a dermatologist, the period before summer leisure is an excellent time to check for "skin growths" on your body. You can examine areas normally hidden by clothing, and having family or a partner look at you can help discover growths on your back or the back of your head that you might not notice yourself.

While the survey showed "not knowing when to seek medical attention" as the most common answer, I want you to remember the "ABCDE rule." If any of the five items—A (Asymmetry), B (Border irregularity), C (Color variation), D (Diameter 6mm or larger), E (Evolving/changes)—apply, we recommend consulting a dermatologist.

"Changes" are particularly important. In this survey, many people considered seeking medical attention for "bleeding" or "rapid growth," but these are signs of a relatively advanced stage. Noticing subtle changes in color or slight increases in size can lead to early detection.

The Guidelines for the Management of Cutaneous Malignant Tumors by the Japanese Dermatological Association emphasize the importance of early detection and treatment. Melanoma, in particular, has a good prognosis if detected and treated early, but it can become difficult to treat if it progresses. Before you wear a swimsuit to the beach or pool, make it a habit to check your entire body in a mirror while bathing.

On the other hand, benign growths can also cause problems if left untreated. Atheromas can cause severe pain and swelling if infected, and treatment will take longer as surgery can only be performed after the inflammation subsides. To enjoy summer leisure with peace of mind, we recommend consulting a medical institution about any concerning growths beforehand.

【Evidence】The Guidelines for the Management of Cutaneous Malignant Tumors by the Japanese Dermatological Association clearly state the importance of early detection and treatment of skin cancer. For melanoma in particular, tumor thickness (Breslow thickness) significantly affects prognosis, so early detection is recommended.

5 Points to Check During Monthly Self-Checks

- Asymmetry: Is the shape of the mole or growth different on each side?

- Border: Are the outlines jagged or blurred?

- Color: Are multiple colors mixed within a single growth?

- Size: Is it 6mm or larger in diameter, or larger than an eraser on a pencil?

- Evolution: Has there been any change in size, color, or shape compared to the past?

Situations Where You Should Consider Consulting a Dermatologist Before Summer Leisure

- If you have a concerning growth in a visible location when wearing a swimsuit or light clothing.

- If you have a growth that has previously become inflamed (e.g., atheroma).

- If you plan to be exposed to a lot of UV radiation and are concerned about an increase or changes in moles.

Kota Takakuwa, M.D.

Has over 15 years of clinical experience and over 30,000 surgical cases in the fields of skin tumors and dermatologic surgery, providing supervision based on medical evidence.

Specialties: Skin Tumors, Dermatologic Surgery, Dermatology, Plastic Surgery

- Miradry Certified Physician

Clinical Achievements (as of 2024, cumulative)

- Skin Tumor/Dermatologic Surgery: Over 30,000 cases

- Treatment for Bromhidrosis: Over 2,000 cases

- Treatment for Rosacea/Facial Redness: Over 1,000 cases

Career

- 2009: Graduated from the Faculty of Medicine, The University of Tokyo

- 2009: Initial training at Tokyo Metropolitan Health and Medical Treatment Corporation Tokyo Metropolitan Health Service Association Hospital

- 2012: Department of Dermatology, Tokyo Metropolitan Police Hospital

- 2012: Department of Dermatology, The University of Tokyo Hospital

- 2019: Treatment Director, IC Clinic

Areas of Supervision: Skin tumors (moles, atheromas, lipomas, etc.), dermatologic surgery, skin cancer, medical information related to general medical columns.

Frequently Asked Questions (Q&A)

Q1. What are the skin signs to check before summer leisure?

A. Follow the "ABCDE rule" and check for asymmetry, border, color, diameter, and evolution. "Sudden changes" are particularly noteworthy. While 82.3% in this survey did not perform self-checks before leisure, many changes can be noticed simply by checking your entire body in a mirror after bathing. For areas you cannot see yourself, such as your back, we recommend asking family members to check.

Q2. What is the correct method for self-checking skin growths?

A. The basic method is to check your entire body in a mirror in a well-lit area once a month after bathing.

The survey showed an awareness rate of only 8.7% for the ABCDE rule. Specifically, use a hand mirror and a full-length mirror to check from your scalp to the soles of your feet. Pay attention to new growths or changes in existing ones (size, color, shape). Taking photos with your smartphone can be helpful for comparison over time.

Q3. What are the characteristics of skin growths that should not be left untreated?

A. Seek medical attention promptly if you notice bleeding, rapid increase in size, color changes, unclear borders, or asymmetry.

The survey found that 67.7% had experience leaving concerning growths untreated. In particular, if you experience "bleeding without being touched," "a noticeable increase in size within a few weeks," or "darkening of color compared to before," do not try to manage it yourself; consult a dermatologist. Even benign atheromas can lead to prolonged treatment if they become infected.

Q4. At what point should I consult a dermatologist for a skin growth?

A. A diameter of 6mm or larger, or a feeling that it's "different from before," are indicators for consultation.

In the survey, 54.2% cited "not knowing when to seek medical attention" as a reason for leaving growths untreated. Specific guidelines include growths larger than an eraser on a pencil (approx. 6mm), those that have changed within the last 3 months, or itching or pain that persists for over 2 weeks. Consulting a specialist medical institution early if you have concerns will allow you to enjoy the summer with peace of mind.

Q5. Should atheromas be removed before summer?

A. Considering the risk of infection and the visibility of scars, treatment before summer may be desirable in some cases.

Atheromas are prone to infection and inflammation during the summer months when sweating is common, and immediate radical surgery is not possible if inflammation occurs. Additionally, scars may become more noticeable due to pigmentation from UV exposure. If you plan to wear a swimsuit, we recommend consulting a dermatologist before summer. Most surgeries can be performed on an outpatient basis.

Risks of Leaving Growths Untreated

- In cases of malignant tumors, leaving them untreated can lead to metastasis and progression, making treatment difficult.

- In cases of atheromas, infection and inflammation can cause severe pain and swelling, prolonging the treatment period.

- Exposure to UV radiation carries the risk of changing or worsening existing moles or tumors.

Who Should Consult Us | Consultation Guidelines

- If you have a growth that meets any of the ABCDE criteria.

- If there has been a change in size, color, or shape within the last 3 months.

- If bleeding or discharge is observed.

- If itching or pain persists for more than 2 weeks.

- If you have a history of inflamed growths (e.g., atheromas).

Clinic Information

Features of IC Clinic

- Doctors with over 15 years of clinical experience in skin tumors and dermatologic surgery are on staff.

- Outpatient surgery for various growths such as atheromas, lipomas, and moles is available.

- Thorough diagnosis using dermoscopy is performed.

- Six branches (Shinjuku, Shibuya, Ueno, Ikebukuro, Tokyo, Omiya) are open on weekends.

IC Clinic Shinjuku: IMAS Aoi Bldg. 2F, 2-5-3 Yoyogi, Shibuya-ku, Tokyo

IC Clinic Shibuya: New Sansui Bldg. 5F, 3-16-2 Shibuya, Shibuya-ku, Tokyo

IC Clinic Ueno: Sankyu Bldg. 1F, 3-16-5 Higashi-Ueno, Taito-ku, Tokyo

IC Clinic Ikebukuro: Maeda Bldg. 9F, 2-15-3 Minamiikebukuro, Toshima-ku, Tokyo

IC Clinic Tokyo: Nihonbashi Front 3F, 3-6-2 Nihonbashi, Chuo-ku, Tokyo

IC Clinic Omiya: Fukubi Medical 2F, B-ku, 1-60 Daimoncho, Omiya-ku, Saitama-shi, Saitama

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