Dermatological guide for primary care physicians: full body skin checks, skin cancer detection, and patient education on self-skin checks and sun protection

Abstract

Dermatological conditions and skin cancers are common health concerns that require early detection and intervention. Primary care physicians play a crucial role in recognizing these conditions and serving as the first line of defense against skin cancers. This guide provides a systematic approach to conducting thorough skin examinations and enhancing understanding of common presentations of precancerous and cancerous lesions. We emphasize the importance of performing annual full-body skin exams to facilitate early detection and management of skin conditions, including a step-by-step, systematic protocol for conducting these exams, comprising preparing the patient, documenting findings, educating the patient, and considering biopsy or referral for suspicious lesions. Furthermore, we explore the atypical features of skin lesions that raise clinical suspicion and warrant further investigation. We describe the characteristics of common skin cancers, such as basal cell carcinoma, squamous cell carcinoma, and melanoma. We stress the importance of patient education on self-skin checks and sun protection measures. By incorporating the knowledge and skills presented in this guide, primary care physicians can confidently perform thorough full-body skin checks, identify common dermatological findings and early signs of skin cancers, and provide comprehensive care to patients. This will help ensure optimal outcomes in dermatological health.

Dermatological conditions and skin cancers are prevalent health concerns that often require early detection and intervention. Primary care physicians play a vital role in recognizing these conditions during routine patient encounters and serve as the first-line intervention for skin cancers. It is estimated that in 2023 in the US, 106,110 new cases of melanoma, 5.4 million new cases of basal cell carcinoma, and 2.8 million new cases of squamous cell carcinoma will be diagnosed, and 7990 people will die from melanoma, 2000 people will die from basal cell carcinoma, and 4480 people will die from squamous cell carcinoma.^1,2 People who live in rural areas have a higher risk of developing skin cancer than people who live in urban areas, due to increased exposure to ultraviolet (UV) radiation, less access to skin cancer prevention education, and less access to skin cancer screening.^3–5 Rural areas also have an increased risk of exposure to arsenic in well water, which has been linked to development of basal and squamous cell carcinoma.⁶ The burden of melanoma and nonmelanoma skin cancers, including on mortality, years lived with disability, years of life lost, and disability-adjusted life years, is second only to cardiovascular disease.⁷ There is a need for universal skin cancer education and screenings among patients in rural areas, which can be easily targeted through primary care physicians.

Comprehensive assessment of the skin through full-body skin checks allows for timely diagnosis and appropriate management. This guide aims to provide primary care physicians with a systematic approach to skin examinations and enhance their understanding of common dermatological findings and skin cancers encountered in clinical practice.⁸ Primary care physicians should develop proficiency in recognizing characteristic features of both normal and abnormal lesions.

In this guide, we outline a comprehensive framework for conducting full-body skin checks. We explore the most common types of skin cancers, discussing their distinguishing features and diagnostic approaches. We provide a list of recommended resources and references that can serve as valuable tools for further reading and expanding knowledge in the field. We also guide primary care physicians in educating patients about self-skin checks and appropriate sun protection measures, thus empowering individuals to monitor their skin for any concerning changes and to seek medical attention promptly when necessary.

ANNUAL FULL-BODY SKIN EXAMS

Performing a thorough and systematic full-body skin exam is essential for the early detection and management of skin conditions.⁸ A vitally important skill is following a systematic step-by-step protocol throughout the body, ensuring each area of the body is checked, including areas such as the middle of the scalp, the mucosal lining of the eyes, the lips, inside the mouth, and the genital area if not checked regularly by another provider.

1. Preparing the patient

   • Explain the procedure to the patient, ensuring their comfort and privacy.
   • Provide a gown or drape for the patient to wear during the exam.
   • Obtain a thorough medical history, including previous skin conditions, family history of skin diseases, and any concerning lesions or symptoms reported by the patient.
2. Equipment and setting

   • Ensure adequate lighting in the examination room to facilitate accurate visualization of skin lesions.
   • Have a magnifying glass or dermatoscope available for closer examination of suspicious lesions.
   • Prepare a measuring tape or ruler to assess lesion size if necessary.
   • Have a pen and paper or electronic device for documentation.
3. Systematic examination

   • Start with the scalp, parting the hair and inspecting the entire scalp surface.
   • Move to the face, examining the forehead, eyebrows, eyelids, nose, cheeks, lips, and chin. Pay attention to any asymmetry, color changes, or abnormal lesions.
   • Examine the ears, including the external ear canal.
   • Proceed to the neck, evaluating the front, sides, and back for any skin abnormalities.
   • Evaluate the upper extremities, including the palms, fingers, and nails. Inspect the skin between the fingers and under the nails.
   • Move to the trunk, examining the chest, abdomen, back, and sides. Lift the breasts if applicable.
   • Assess the lower extremities, including the thighs, legs, ankles, and feet. Examine the spaces between the toes and under the nails.
   • Discuss with the patient the importance of checking sensitive areas such as the genital area, buttocks, and perianal area. After obtaining permission from the patient (who is allowed to refuse due to discomfort), ensure that the patient is properly draped to maintain maximal privacy and comfort. Ensure that an appropriate chaperone is present and carefully explain all portions of the exam in clear and easily understood terms.
   • It is appropriate to defer the genital portion of the exam to gynecology if that is the patient’s preference. At all times, the patient’s wishes should be respected and, although the patient should be informed as to the rationale for this part of the exam, it should only be performed with the patient’s express permission.
   • Lastly, inspect the nails and mucous membranes, including the oral cavity.
4. Documentation

   • Document any relevant findings during the examination, including the location, size by triangulated measurements, color, shape, and characteristics of any lesions.
   • Take photographs, both zoomed in and zoomed out, to document specific lesions and their location for future reference.
5. Patient education

   • Discuss any significant findings or concerns with the patient and present family members. If there is no family member there, consider having the patient take a picture for their own documentation.
   • Educate the patient on self-skin examinations and the importance of regular follow-ups for monitoring changes in their skin.
6. Referral or biopsy⁹

   • If any suspicious lesions or concerning findings are identified, consider referral to a dermatologist for further evaluation or perform a skin biopsy as indicated.
   • For suspected melanoma, the preferred biopsy technique is narrow excision or complete biopsy with 1 to 3 mm margins. This method should involve the entire depth of the lesion to prevent excluding the base. While this may be done with a punch biopsy, fusiform/elliptical or deep shave/saucerization can also be used to excise the lesion at a plane below the lowermost plane of the lesion. Complete biopsies are preferred but partial or incomplete (incisional) biopsies can also be used for the face, acral locations, large lesions, or lesions that are of low clinical suspicion. However, partial biopsies have the risk of inaccurately staging malignancies or underestimating Breslow depth.
   • In addition, if using a shave or saucerization biopsy, consider using topical hemostatic agents instead of electrocautery to stop bleeding, This might include aluminum chloride, ferric subsulphate, or other topical coagulants to ensure that the electrocauterization does not destroy the rest of the melanoma and create a false negative in future biopsies, if needed.

SKIN CANCERS

Identifying atypical features of skin lesions is a crucial skill for healthcare providers, particularly primary care physicians, in the evaluation of skin conditions and the early detection of potentially malignant lesions. While most skin lesions are benign and pose no significant health risks, certain atypical features can raise suspicion and indicate the need for further investigation. Recognizing these atypical features is essential for timely referral, appropriate management, and improved patient outcomes.^10,11 We describe the key atypical features of skin lesions that should trigger clinical suspicion, helping primary care physicians navigate the complex landscape of skin evaluations and enhance their ability to identify potentially concerning lesions. By understanding and recognizing these features, healthcare providers can play a vital role in the early detection and intervention of skin malignancies, ensuring optimal care for their patients.

The following are atypical features that warrant skin biopsy or raise clinical suspicion:¹²

• Asymmetry: Look for lesions with irregular shape or asymmetrical growth.

• Borders: Check for irregular, blurred, or jagged edges.

• Color: Note any variations in color, including multiple colors within a single lesion.

• Diameter: Pay attention to changes in size, particularly if a lesion exceeds 6 mm in diameter.

• Evolution: Monitor any changes in shape, size, color, or symptoms over time.

• Rapid growth: Lesions that rapidly increase in size or undergo significant changes within a short period may be suspicious for malignancy.

• Bleeding or crusting: Lesions that frequently bleed, ooze, form scabs, or fail to heal properly may indicate underlying malignancy or other pathological processes.

• Episodic presentation: A lesion that recurs in the same location can be an indication of malignancy.

• Not healing as expected: Lesions that do not heal properly with adequate wound care and time should be further investigated.

• Itchiness or pain: Lesions associated with persistent itchiness or pain, especially if disproportionate to their appearance, should raise concern for malignancy.

• Location: Lesions occurring in high-risk areas, such as the face, scalp, ears, palms, soles, mucosal surfaces, or areas of chronic sun exposure, may warrant closer examination and evaluation.

• Family history: A family history of melanoma or other skin malignancies increases the risk and should raise clinical suspicion.

• Personal history: Further investigation should be prompted if the patient has a personal history of skin cancer or other high risk factors:

• History of radiation

• History or current hematopoietic malignancy

• History of transplant or chronic immunosuppressive medications for autoimmune disorders

• History of photosensitizing medications (e.g., voriconazole, hydrochlorothiazide)

CHARACTERISTICS OF COMMON SKIN CANCERS

Table 1 summarizes the characteristics of basal cell carcinoma, squamous cell carcinoma, melanoma, and actinic keratosis.^13–29 Figures 1–4 illustrate each type.

Table 1.

Characteristics of skin cancer

Type	Classic clinical description	Rarer characteristics	Common areas
Basal cell carcinoma13,14	Visual: Often presents as a pearly, flesh-colored, or pink papule or nodule with telangiectasia (visible blood vessels) and a rolled, raised border. It may have central ulceration or crusting. Touch: Lesions are typically smooth, nontender, and may feel fragile or "waxy" to touch.	Morpheaform or sclerosing: These variants infiltrate deeper into the skin, with subtle clinical features, such as a firm, scar-like plaque or indurated patch that can mimic benign conditions. Pigmented: This variant displays brown or black pigmentation, which can resemble melanoma, making it important to differentiate between the two. Metastatic: Although rare, basal cell carcinoma can metastasize to distant sites, especially in cases of neglected or aggressive tumors.	Face Ears Scalp and neck
Squamous cell carcinoma17–20	Visual: Typically presents as a scaly, erythematous plaque or nodule, often with central ulceration and crusting. Touch: Lesions may feel firm, indurated, or rough upon palpation.	Rapid growth: Can exhibit accelerated growth over weeks to months, exceeding the expected rate for benign lesions. Nonhealing ulceration: Persistent ulceration that fails to heal despite appropriate wound care measures may raise suspicion. Perineural invasion: Has the potential to invade peripheral nerves, resulting in neurologic symptoms such as pain or paresthesia in the affected area.	Sun-exposed areas: face, ears, lips, scalp, and dorsal hands. Mucous membranes: oral cavity, lips, genitalia, and anus. Note that human papillomaviruses is associated with increased risk of development in mucosal and cutaneous skin. Chronic ulcers or scars
Melanoma21–25	Visual: Typically presents as an asymmetric, irregularly shaped pigmented lesion with variegated colors, including shades of brown, black, blue, or red. It may have an uneven or notched border and can evolve. Touch: May be raised and may feel firm or nodular; however, early melanomas are often flat with no palpable areas. The texture can vary from smooth to rough or ulcerated. Many early melanomas demonstrate no textural change, so the lack of texture does not rule out malignancy.	Amelanotic: This variant lacks typical pigmentation, appearing as a pink, flesh-colored, or red lesion. It can be challenging to recognize, leading to delayed diagnosis. This subtype of melanoma is most common in patients with skin of color. Lentigo maligna: This subtype often arises on sun-damaged skin, particularly in older individuals. It presents as a large, flat, tan-brown lesion with irregular borders and variegated colors. Acral lentiginous: Occurring on the palms, soles, or under the nails, this subtype is less related to sun exposure. It may present as a dark-colored macule, nodule, or streak.	Trunk: Chest and back in males, and on the back and legs in females. Face and neck: Nose, cheeks, forehead, and scalp. Note that most nonmelanoma skin cancers are located on the head/neck or sun-exposed extremities. Malignant melanoma is unique in that it may be seen more on the backs of males and lower legs in females.
Actinic keratosis (premalignant)26–29	Visual: Appear as rough, scaly patches or plaques on sun-exposed areas of the skin. They are typically small, measuring a few millimeters to a centimeter in diameter. Colors can range from pink to red, tan, or brown. Touch: May feel rough or gritty, similar to sandpaper. They can be flat or slightly raised, with a dry or rough texture.	Hypertrophic: This variant presents as a thickened, hyperkeratotic lesion with a warty or stuck-on appearance. It may resemble a small horn. Pigmented: Can exhibit increased pigmentation, appearing brown or black. This can lead to confusion with melanoma or lentigo maligna. Cutaneous horns: In rare cases, can give rise to a cutaneous horn, which is a conical projection of keratinized material.	Face: Forehead, nose, cheeks, and temples. Scalp: Hairline and the top of the head Hands and forearms

Figure 1.

(a) Nodular basal cell carcinoma (BCC). (b) Sclerosing BCC. (c) Pigmented BCC. (d) BCC in skin of color. The top is superficial spreading BCC, middle is nodulocystic BCC, bottom is ulcerated BCC. Images provided courtesy of DermNet™ (https://dermnetnz.org/).

Figure 2.

(a) Cutaneous squamous cell carcinoma (SCC). (b) SCC from a persistent ulcer, also known as Marjolin ulcer. (c) SCC in skin of color. Images provided courtesy of DermNet™ (https://dermnetnz.org/).

Figure 3.

(a) Variety of melanoma: the top is superficial spreading, middle is nodular, bottom is melanoma in the nail. (b) Amelanotic melanoma. (c) Lentigo maligna melanoma. (d) Acral lentiginous melanoma. (e) Melanoma in skin of color. Images provided courtesy of DermNet™ (https://dermnetnz.org/).

Figure 4.

(a) Actinic keratoses. (b) Pigmented actinic keratoses. (c) Cutaneous horn. Images provided courtesy of DermNet™ (https://dermnetnz.org/).

PATIENT INSTRUCTIONS FOR AT-HOME SKINCARE

Primary care physicians play a crucial role in promoting healthy skin and educating patients on proper skincare practices and sun protection. This section focuses on providing practical recommendations for at-home skincare and sun protection. We emphasize the importance of sun protection measures and performing self-skin checks. By empowering our patients with these simple yet effective strategies, we can help them maintain healthy skin, prevent sun damage, and detect any concerning skin changes promptly.

The basics of at-home sun protection consist of the following points:^30–32

• Apply broad-spectrum sunscreen with at least an SPF of 30 using an adequate amount (about a teaspoon for the face and a shot glass for the body) at least 15 minutes before sun exposure.

• Reapply sunscreen every 2 hours or more frequently if sweating heavily or swimming.

• Use products with broad-spectrum protection of at least SPF 30 on the lip as well, and apply on the lips similarly to the face.

• Wear protective clothing, such as wide-brimmed hats, sunglasses, and long-sleeved shirts, when in the sun.

• Seek shade during peak sun hours, typically between 10 am and 4 pm.

• Perform self-skin checks to monitor for any changes or suspicious lesions. It is important to be familiar with your own skin and seek medical attention if you notice any concerning or evolving lesions. Learn the ABCDEs of skin lesions and perform self-checks at least once a month.

SUNSCREEN

It is also important for patients to understand sunscreen, including common misconceptions.^33–46 SPF, or sun protection factor, indicates the amount of protection that the sunscreen provides, but increases in SPF do not translate to a linear increase in protection. For example, SPF 15 sunscreens block approximately 93% of UVB rays; SPF 30, about 97%; SPF 50, about 98%; and SPF 100, around 99%. Thus, as the SPF value increases, the subsequent increase in sun protection plateaus. No sunscreen offers total protection, so coverage through clothing can help increase sun protection.

There are two types of sunscreen filters: mineral (inorganic) and chemical (organic). Mineral sunscreens contain active ingredients like zinc oxide and titanium dioxide. These minerals work by forming a physical barrier on the skin that reflects and scatters UV rays, thus providing broad-spectrum protection against both UVA and UVB rays. Nonmineral physical sunscreens may also include chemical UV filters in their formulations, which absorb UV rays and convert them into less harmful energy.

Although both types of filters are effective in preventing skin damage, some providers and patients are partial towards mineral sunscreen filters for several potentially clinically significant reasons. Mineral sunscreens are often praised for their gentleness on the skin, making them suitable for individuals with sensitive skin or those prone to allergies or irritation. They are also considered reef-safe, as some chemical filters have been found to be harmful to coral reefs, including oxybenzone, a chemical filter that is common in sunscreens found in US markets. In addition, oxybenzone has also been found to be a hormone disruptor in endocrine, reproductive, metabolic, and renal systems in animal studies. Currently, data on the effects of oxybenzone in humans is largely inconclusive. Other potentially concerning yet inconclusive research findings include an association between sunscreen use and frontal fibrosing alopecia and allergic contact dermatitis. Both of these can involve oxybenzone, a sunscreen filter and a common skin sensitizer. Providers should make patients aware of this information as part of transparency of care but also clarify that these findings have not been completely proven by well-designed human trials.

While mineral and chemical filters are the main ingredients in sunscreen that offer photoprotection, additional cosmetic ingredients applied topically can reinforce photoprotection. These ingredients can include antioxidants, such as polyphenols or phytochemicals. Examples of these antioxidants include resveratrol, green tea polyphenols, and grape seed pro-anthocyanidins. Microalgae can also be used in cosmetics since they are resistant to UV exposure because it contains photoprotective compounds, including mycosporine-like amino acids, sporopollenin, and scytonemin. Both microalgae and antioxidants can have the potential to repair UV-induced DNA damage. Oral supplementation of antioxidants can have a similar effect and providers can offer this as an option to those who are particularly susceptible to sun damage as an adjunct to topical sunscreen.

There are many effective sunscreens on the market; however, increasing public distrust of commercial products for containing “chemicals” has increased the popularity of “homemade” and “do-it-yourself” sunscreens. However, these sunscreens are not tested for efficacy in filtering UV rays and thus can be potentially dangerous for patients to use. Providers should warn patients against these online recipes and emphasize the importance of using a commercially available and FDA-approved sunscreen.

ADDITIONAL RESOURCES

To aid primary care physicians in their clinical practice, it is essential to have access to additional resources that provide in-depth information on these rare skin diseases. The resources listed in Table 2 can serve as valuable references and guides when encountering uncommon dermatological conditions. These resources offer detailed descriptions, diagnostic criteria, treatment options, and up-to-date information on the latest research and management strategies for rare skin diseases.

Table 2.

Resources on skin cancer

Type	Examples
Dermatology textbooks47–49	Dermatology: 2-volume set (Bolognia et al)
	Fitzpatrick's Dermatology (Sewon Kang et al)
	Habif's Clinical Dermatology (Dinulos)
Dermatology journals	Journal of the American Academy of Dermatology
	Dermatology and Therapy
	Journal of Investigative Dermatology
Online resources	DermNet NZ
	American Academy of Dermatology website
	UpToDate
Additional recommended skincare routine and products	Skin care routine recommendations from American Academy of Dermatology: https://www.aad.org/public/everyday-care/skin-care-basics/care
	Recommended products on SkinCancer.org: https://www.skincancer.org/recommended-products/

CONCLUSION

Performing regular full-body skin checks allows primary care physicians to detect potential premalignant lesions and skin cancers effectively. Familiarity with the defining characteristics and diagnostic tools for skin cancers enhances the ability to provide early intervention. Additionally, recommending basic sun protection practices and educating patients on self-skin checks contributes to overall skin health and early detection of concerning lesions.

Disclosure statement/Funding

The authors report no funding or conflicts of interest.