What are the ABCDE criteria?

A = Asymmetry (one half is unlike the other). B = Border irregularity (edges are ragged, notched, or blurred). C = Color (uneven color — black, brown, tan, red, white, or blue). D = Diameter >6mm (larger than a pencil eraser, though melanomas can be smaller). E = Evolving (changing in size, shape, or color over time). Any of these warrants medical evaluation.

Should I see a doctor if I have any ABCDE sign?

Yes. While many benign moles may have one ABCDE feature, the presence of any suspicious sign — especially Evolution (change) — warrants dermatology evaluation. The 'E' criterion is often considered the most important, as melanomas typically change over weeks to months. Don't wait for multiple criteria before seeking evaluation.

What is the 'ugly duckling' sign?

The ugly duckling sign is a complementary screening approach: a mole that looks different from all other moles on the body (the 'outlier') is suspicious regardless of ABCDE criteria. Most of a person's moles resemble each other. A mole that is clearly different in appearance from the rest deserves closer evaluation.

Online Medical Tools — ABCDE Melanoma Check

Printed on 8/14/2026

For informational purposes only. This is not medical advice.

Dermatology

ABCDE Melanoma Check

The ABCDE criteria are the most widely recognized melanoma warning signs for skin self-examination. A = Asymmetry (one half doesn't match the other), B = Border irregularity (edges are ragged, notched, or blurred), C = Color variation (uneven distribution of color including brown, black, red, white, or blue), D = Diameter greater than 6mm (about pencil eraser size), E = Evolving (changing in size, shape, or color). While no single criterion is diagnostic, the presence of multiple ABCDE features increases concern for melanoma and warrants dermatology referral for dermoscopy and possible biopsy. Early detection is critical — 5-year survival for stage I melanoma is >95%. For melanoma patients undergoing chemotherapy, assess performance status with ECOG Performance Status and calculate chemotherapy doses using BSA Calculator. Monitor renal function with eGFR Calculator. Assess skin disease quality of life with DLQI Score.

Formula: Count of 5 criteria present: Asymmetry, Border, Color, Diameter >6mm, Evolving.

A — Asymmetry: Is the mole asymmetric?

B — Border: Are the borders irregular, ragged, or blurred?

C — Color: Does the mole have multiple colors (brown, black, red, white, blue)?

D — Diameter: Is the mole larger than 6mm (pencil eraser)?

E — Evolving: Has the mole changed in size, shape, or color?

Save your results with a free account

Keep a history of calculations, favorite tools, and access your dashboard anytime.

Create free account Sign in

How It Works

Examine the mole systematically using each ABCDE criterion

Assess the lesion in good natural lighting for Asymmetry (one half unlike the other), Border irregularity (ragged/notched edges), Color variation (multiple shades including black, blue, white, or red), Diameter greater than 6mm, and Evolving (any recent change in size, shape, or color).

Note all positive criteria, especially E (evolving)

Record which criteria are present. Evolution is the single most clinically important criterion because it indicates active change — melanomas typically grow and change over weeks to months. Any mole that is different from last month warrants evaluation regardless of other features.

Count positive criteria and decide on referral

Zero criteria: reassuring but not definitive — continue monthly self-exams. One criterion: monitor closely, consider dermatology referral (especially if E is positive). Two or more criteria: prompt dermatology referral for dermoscopy and possible biopsy. Any rapidly changing or bleeding lesion warrants urgent referral.

Who Uses the ABCDE Melanoma Check

Skin Self-Examination

General public, high-risk individuals

The American Academy of Dermatology recommends monthly full-body skin self-exams. ABCDE provides a simple, memorable framework for evaluating moles. Higher-risk individuals (fair skin, family history, >50 moles, prior melanoma) should use this checklist regularly.

Primary Care Screening

Primary care physicians, nurse practitioners

ABCDE provides a structured framework for opportunistic skin screening during routine visits. Any lesion meeting criteria warrants dermatology referral with documentation of the specific ABCDE findings present. Dermoscopy-equipped GPs achieve significantly higher sensitivity.

Dermatology Triage

Dermatologists, dermatology nurses

ABCDE criteria guide initial naked-eye triage before dermoscopy. Documenting positive criteria in referral letters helps dermatologists prioritize urgency. Lesions meeting multiple criteria receive faster appointments than single-criterion referrals.

Telemedicine Skin Assessment

Telehealth providers, digital health platforms

ABCDE criteria are the basis for many AI-powered skin lesion apps. When evaluating teledermatology photos, clinicians use ABCDE as the initial scoring framework before recommending in-person dermoscopy or biopsy.

Public Health & Skin Cancer Prevention

Dermatology nurses, public health workers

ABCDE is the foundation of national skin cancer awareness campaigns (Skin Cancer Foundation, Cancer Research UK). Melanoma Awareness Month (May) specifically promotes ABCDE education. Early-stage melanoma (Stage I) has >95% 5-year survival — detection makes the difference.

Medical Education

Medical students, primary care residents

ABCDE is a core learning objective for all clinicians who perform physical examinations. The mnemonic is designed for reliable recall in any clinical setting without reference materials, making it particularly valuable for non-specialist providers.

Pro Tips

E (Evolving) is the single most important criterion

A mole that changes — grows larger, changes color, changes shape, or starts bleeding — is the most reliable warning sign of melanoma, even if all other ABCDE criteria appear normal. Ask patients: 'Has this mole changed in the past 6 months?' If yes, refer regardless of other features.

Use the 'ugly duckling' sign as a complementary approach

Most of a person's moles look similar to each other. A mole that stands out as distinctly different from the rest of the person's moles — the 'ugly duckling' — is suspicious regardless of ABCDE criteria. This complementary approach catches many melanomas missed by ABCDE alone.

Nodular melanoma and amelanotic melanoma can fail all ABCDE criteria

Nodular melanoma (15% of melanomas) is often symmetric, uniformly colored, and smaller than 6mm early in its rapid growth phase. Amelanotic melanoma lacks pigment and appears pink. For elevated, firm, growing lesions, use the EFG criteria (Elevated, Firm, Growing rapidly) as a complement.

Annual total-body skin exams after age 40 are recommended

The American Cancer Society and AAD recommend annual professional skin exams for adults with fair skin, family history of melanoma, personal history of skin cancer, significant cumulative sun exposure, or more than 50 moles. Self-exams should be done monthly for high-risk individuals.

Photograph suspicious moles for monitoring

Take reference photos of all suspicious moles in natural light, held at a consistent distance. Compare monthly. Any mole that grows larger, darkens, or changes in any way between photos meets the E criterion and should be evaluated by a dermatologist.

Dermoscopy dramatically improves sensitivity beyond naked-eye ABCDE

Dermoscopy (dermatoscopy) increases melanoma detection sensitivity from about 65–70% with naked eye to 85–90% in trained hands. Patients with multiple suspicious moles or high melanoma risk should see a dermatologist with dermoscopy access, not rely on naked-eye ABCDE alone.

Blue-white veil and irregular pigment network are dermoscopic red flags

For clinicians trained in dermoscopy: blue-white veil, atypical pigment network, regression structures, and irregular dots/globules are the dermoscopic criteria most predictive of melanoma, augmenting naked-eye ABCDE assessment.

Common Questions About Your Results

The criteria apply across skin tones, but presentation may differ. Melanoma in darker-skinned individuals more commonly occurs on acral sites (palms, soles, under nails) and may appear as a band-like dark line under a fingernail (melanonychia). The ABCDE criteria were primarily derived from fair-skinned populations, so clinicians should maintain a broader index of suspicion for acral and mucosal sites in patients with darker skin.

Evidence-Based Methodology

The ABCDE criteria were developed by Friedman, Rigel, and Kopf (1985) at NYU and have been the standard for melanoma self-examination for 40 years. Stage I melanoma (localized, <1mm Breslow thickness) has a 5-year survival exceeding 95% (SEER data). The American Academy of Dermatology recommends annual professional skin exams for high-risk individuals.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

Your result indicates how many of the five ABCDE melanoma warning criteria are present in the mole being evaluated. Having zero criteria is reassuring but does not completely exclude melanoma. One criterion present warrants monitoring and consideration of dermatology referral, particularly if the criterion is Evolution (change over time). Two or more criteria present significantly increases concern for melanoma and warrants prompt dermatology referral for dermoscopy and possible biopsy.

No set number of ABCDE criteria is diagnostic of melanoma — the checklist is a screening tool to help identify suspicious lesions. Some melanomas (particularly amelanotic or nodular melanomas) may not meet any ABCDE criteria. Conversely, some benign lesions (such as seborrheic keratoses or dysplastic nevi) may meet multiple criteria. A biopsy is the only way to definitively diagnose melanoma.

When to Use This Tool

Use this checklist for skin self-examination of moles and pigmented lesions. The American Academy of Dermatology recommends regular self-examination of the skin for new or changing moles. It is particularly useful when a patient or family member notices a mole that looks different from others (the ugly duckling sign) or when a mole appears to be changing.

Clinicians can use this as a quick screening framework during skin examinations, though dermoscopy provides far greater diagnostic accuracy than naked-eye ABCDE assessment alone. Any lesion meeting ABCDE criteria should be evaluated by a dermatologist with dermoscopy expertise.

Limitations

The ABCDE criteria were designed primarily for superficial spreading melanoma, which is the most common subtype. They perform poorly for nodular melanoma (which is often symmetric, has regular borders, and is uniformly colored) and amelanotic melanoma (which lacks pigment). The EFG criteria (Elevated, Firm, Growing) have been proposed as a complement for nodular melanoma detection.

The ABCDE checklist is a screening tool with imperfect sensitivity and specificity. It cannot replace dermoscopy or histopathologic examination. Small melanomas (under 6mm) are increasingly recognized, which limits the usefulness of the diameter criterion. The Evolution criterion is often considered the most important single factor, as melanomas typically change over weeks to months, but it requires a history of observation. Patients with many atypical moles (dysplastic nevus syndrome) may have multiple moles meeting ABCDE criteria, making individual assessment more challenging.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Changelog

April 21, 2026 · trust-baseline
Clinical trust metadata enabled for this tool page with structured review/version fields.

Related Tools