For the hand surgeon, the skin exam is an observational exam that is performed while evaluating related structures (eg, bones, joints) in organ systems other than the integumentary system. In hand surgery practice, this typically consists of an incomplete examination of the uncovered portions of the upper extremities. If the hand surgeon, hand trainee, hand therapist, or hand surgery physician assistant identifies abnormal findings on the skin examination, then a referral to a dermatologist is indicated, especially if the skin diagnosis is unknown to the patient and a prior workup has not yet been performed.
Description of Exam
For a proper skin examination of the upper extremities, the patient should ideally be in a short sleeve or sleeveless top. The exam room must have excellent lighting, but supplementary lighting from a flashlight or otoscope should also be available, as well as a handheld magnification glass. The fingernail exam should be included in the hand surgeon’s skin exam. The palmar and dorsal surfaces of the forearm, wrist, hand, and digits should be examined in a systematic manner.
The normal upper extremity skin should show smooth intact skin with coloration consistent with the patient’s race. The skin on the dorsum of the hand should be loose and mobile, while the palmar skin is less mobile because of its numerous retention ligaments. The skin texture, mobility, and thickness will vary with the patient’s age and hand use.
As noted, specific areas of the upper extremity skin should be visualized in an organized manner. Next, any abnormal lesion(s) should be evaluated using a six-step process:
Step 1: Identify the lesion size
Step 2: Identify lesions without elevation or depressions:
- Macule – flat skin lesion <1 cm
- Patch – flat skin lesion >1 cm
Step 3: Identify elevated lesions:
- Plaque – flat lesion usually >1 cm
- Papule – solid lesion <1 cm
- Nodule – solid lesion >1 cm
- Vesicle – fluid-filled lesion <1 cm
- Pustule – pus-filled lesion <1 cm
- Bulla – fluid-filled lesion >1 cm (fluid often clear or straw-colored)
- Although not part of the exam, symptomatology must also be considered. A history of color change, shape change and tenderness are all red flags for more dangerous lesions.
Step 4: Define whether the lesion is well demarcated or not and define its distribution. Note if the skin lesion is on the extensor surface, on the palmar surface, on a photodistributed area, or is diffuse. The upper extremity photodistributed areas include the dorsum of the digits, hand, wrists, and forearms.
Step 5: Identify the lesion’s color. Common lesion colors include white, red, purple, brown, yellow, black, and blue.
Step 6: Identify the secondary morphology, such as:
- Serum (dry crust)
- Lichenification – thickened skin secondary to epidermal hyperplasia seen in chronic dermatitis
After completing the skin exam, the examiner should determine if the skin abnormalities are primarily a rash, benign lesion(s), or malignant lesion(s), and then consider the common skin differential diagnoses of the hand listed below.
Contact dermatitis (allergic and irritant)
Contact dermatitis can be secondary to an allergen or irritant. It is a reactive eczematous inflammation that occurs after exposure to a biologic or chemical irritating agent or exposure to an allergen. At presentation, the skin may be red, swollen, tender, or itchy with possible urticaria (hives) and/or ulcerations. Rash configuration includes geometric areas with angular corners associated with patches and/or plaques. Poison ivy produces a contact dermatitis with a linear pattern that includes papules and vesicles.1-3
Dyshidrotic eczema is also called pompholyx or dyshidrosis. Dyshidrotic eczema is a type of dermatitis with burning pain and associated itching involving the palmar glabrous skin of the hand and sides of the fingers. This type of eczema is further characterized by eruptive symmetric “sago-like” vesicles. It is a diagnosis of exclusion, and the exact cause is unknown.3-5
Psoriasis is a sharply demarcated rash caused by increased epidermal proliferation. The skin exam shows pink papules, patches, and plaques often with a silvery scale especially on the palms and dorsal knuckle pads. Although psoriasis can be seen throughout the upper extremities, early changes are common over the olecranon and posterior elbow. The thenar and hypothenar areas are often involved as well. The psoriatic lesions will be surrounded by scales (built up stratum corneum). Over half of the patients will have nail involvement with nail plate pitting, oil spotting and thick deformed nails.1,3,6
Erythema multiforme can be either major or minor, with the minor form featuring a symmetric red rash with a propensity to involve the extremities. The rash is more common on the extensor surfaces. The presence of target lesions with three zones of color—often on the palms—is diagnostic. These lesions can look like insect bites or papular urticaria. History of a recent herpes infection is common. This rash can be associated with the use of certain drugs. The rashes are called erythema multiforme major when the mucosal surfaces are involved.1,3,7
Lichen planus is an autoimmune inflammatory skin disease. This rash is characterized by flat papules sometimes with white dots and lines, often on the flexor surface of the forearm and wrist. This rash is distinguished by the six P’s:1
- Palmar wrist
Chronic cases of lichen planus can have painful erosions and nail involvement. There is an association with the hepatitis C virus (HCV). The white lines and dots are called Wickham striae and often require magnification for proper visualization. The rash has streaking that can resemble trauma induced scratch marks (Koebner phenomenon).1,8,9
Actinic purpura is also known as Bateman’s purpura, senile purpura, and dermatoporosis. It presents with ecchymotic round or oval macules or patches on the dorsum of the hand, wrist, and forearm. The lesions have irregular borders but sharp edges. Typical lesions, which are >3 mm in diameter, occur in fragile thin skin of older individuals, especially males with history of sun exposure and/or anticoagulant and corticosteroid use. Chronic lesions may mature into white stellate pseudoscars.1,3,10,11
Also known as “ringworm,” this disorder is a fairly common dermatophyte fungal infection. This fungal infection often occurs in the feet and secondarily in a hand (“one hand/ two feet”). This infection causes dry angular scaling of the palm. The palm can also be itchy with erythematous patches and/or pustules.1,3,12,13
Benign skin lesions
The benign lesions of seborrheic keratosis have a tan to brown-to-black color and look like “greasy, stuck on” papules or plaques.1The elevated lesions have a definite margin (ranging from 2 mm to 2 cm in size) with a wart-like appearance on the surface. Symptoms are commonly related to secondary trauma. A biopsy is indicated if the diagnosis is in question.1,3 It can occur on the upper extremities, but usually not on the palms.
Solar lentigo (actinic lentigines) is a patch of benign skin lesions. The macules of solar lentigo can have color that varies from tan to dark brown; however, the lesions always have a uniform, diffuse, homogenous pigmentation. The lesions usually have distinct borders, but will have moth-eaten or scalloped edges. In the upper extremity, they will occur on sun-exposed surfaces, particularly the dorsum of the hand, wrist, and forearm. These variably sized lesions are very common, as >90% of Caucasians over 70 years of age show signs of solar lentigo. Solar lentigo must be distinguished from lentigo maligna lesions, which are potentially malignant. Lentigo maligna lesions have irregular pigmentation, asymmetrical pigmented follicular opening, rhomboidal structures around hair follicules, annular-granular structures, and a gray pseudo-network appearance.1,3,14Rhomboidal structures are best seen with magnification (dermatoscope).
Wart (verruca vulgaris)
The wart, or verruca vulgaris, is common on the hands and fingers, and can occur around and underneath fingernails. Warts are skin-colored hyperkeratotic papules or nodules with a size range of 1 mm to 1 cm, and they can be painful. The lesions are sprinkled with black or red dots, which represent thrombosed capillaries. The surface of a wart is rough and irregular (bumpy). Warts are an infection of the epithelial cells.1,3,15
Dermatofibroma is a common skin lesion occurs in young adults. They are often solitary lesions, and size and color are variable. Size is 5 mm to 2 cm and colors include brown, dark brown, yellow, pink, blue, red, brownish red, and black. These asymptomatic lesions are firm round or ovoid papules or nodules. They are more frequently indurated than elevated. When the lesion is compressed from the sides, the center dimples. This is called the dimple or Fitzpatrick’s sign, but it is not pathognomonic.1,3
Blue nevus, or blue mole, is a benign skin lesion (<1 cm) that occurs in children. It is a blue-gray or blue-black deep dermal papule that consists of melanocytes. These lesions are usually homogenous in color, but can also have two colors. While the blue nevus can occur throughout in the body, the hand is a common site. The cellular blue nevus, which is typically larger, is one of several variants. Because the blue nevus is similar in appearance to nodular melanoma, a biopsy may be needed to assure an accurate diagnosis.1,3,16
Pyogenic granuloma has been called by various names, including lobular capillary hemangioma, granuloma telangiectaticum, granuloma gravidarum, and granuloma paniculatum. It is usually a red skin lesion, but there are subcutaneous and intravenous variants. Some pyogenic granulomatous lesions have a cutaneous and connected subcutaneous component. Pyogenic granulomas typically occur in children and young adults, and the fingers, hands, and forearms are involved in 12-37% of cases.17 These lesions develop rapidly, have an average size of 6.5 mm (2-3 mm to 2 cm range), are sometimes painful, friable, and have a tendency to bleed spontaneously or after minor trauma. Histologically, the pyogenic granuloma is consistent with classic granulation tissue with endothelial cells, connective tissue, capillaries, and venules in an edematous matrix. The lesion is surrounded at its base by a collarette of epidermal cells.3,17,18
Malignant skin lesions
Basal cell carcinoma
Basal cell carcinoma is the most common human cancer and the most common skin cancer,2,8 and cases of the hand and upper extremity account for 10% of these lesions. All ages are susceptible to these lesions, but the average age of occurrence is 68, and most cases are seen in patients over 40. Fair-skinned individuals with a history of short significant exposure to the sun are especially at risk for basal cell carcinoma. The basal cell carcinoma lesion has four subtypes: nodular, pigmented, superficial, and sclerotic morpheaform (infiltration or scarring). On the exam, basal cell carcinomas have well defined edges with an erythematous (red) papule or think plaque with or without scale, crust, or pearly rolled edges. Associated telangiectasias are common. Color varies by subtype. Colors include faint white, pink, red, blue, brown, and black. The lesions may have an atrophic eroded or depressed center. The risk of metastasis is low but increases with lesion size and time on the skin.1,3,19-21
Squamous cell carcinoma
Squamous cell carcinoma accounts for 20% of all skin cancers, making it the second most common type, with 16% of cases occurring in the hand, wrist, and upper extremity.2,8 Squamous cell carcinomas can arise from precursor lesions called actinic keratos. The early noninvasive form of squamous cell carcinoma is squamous cell carcinoma in situ, or Bowen disease. Squamous cell carcinoma typically develops in fair-haired elderly individuals. On the exam, the lesions are hyperkeratotic papules or nodules. These lesions may be scaly, ulcerated, or crusted. The squamous cell carcinoma lesion is usually erythematous to flesh color, with smooth or verrucous surface. Invasive lesions can be particularly fixed to the underlying tissues. These lesions have the potential (40%) to metastasize to the regional lymph nodes.1,3,19,20
Keratoacanthoma (Low Grade Squamous Cell carcinoma)
Keratoacanthoma is a rapidly developing skin lesion that is a variant of a squamous cell carcinoma. Keratoacanthoma is most common in men in their 60s and 70s, and can develop in days to weeks in sun-exposed areas like the dorsum of the hand and wrist. Keratoacanthomas are usually solitary lesions with a size of 1-2 cm. The keratoacanthoma is a well-defined lesion that has a dome-shaped erythematosus or skin-colored nodule with a keratinous core in its center. These lesions are usually painless but may be itchy and can present as a significant cosmetic deformity. Although some cases resolve without treatment, others can be invasive and metastasize to the upper extremity lymph nodes. Therefore, excision surgery is indicated.1,3,19
Melanoma only accounts for 4% of skin cancers, but is responsible for 80% of skin cancer-related deaths. Melanoma typically occurs in white males over the age of 50, with 15% occurring in the upper extremity and 2% in the hand. The four subtypes of melanoma are:
- Lentigo melanoma
- Superficial spreading melanoma
- Nodular melanoma (occurs in the palm)
- Acral lentiginous
About 30% of melanomas start from precursor lesions, which include dysplasia, nevi, and melanoma in situ. The exam description of melanoma is best evaluated by using the acronym ABCDE:
- Border irregularity
- Color variation
- Diameter >6 mm
When the fingernail is involved, the acronym changes to ABCDEF:
- Age and race
- Band breadth (width of streaks in nail; ≥3 mm and irregularities suggest melanoma)
- Change in lesion size (growth)
- Digit involved (thumb is the most common site)
- Extension of pigment into the nail fold (Hutchinson’s sign)
- Family history positive1,3,19,20
- Surface anatomy of hand and wrist
- Blue nevus (fingernail)
- Squamous cell carcinoma
Diagnostic Performance Characteristics
The diagnostic accuracy of the skin exam will depend on the experience of the observer and a thoughtful clinicopathologic correlation. Furthermore, the exam must always be combined with the patient’s history, especially as the history relates to the risk factors associated with skin cancer, the dermatoscope findings, and the results of skin biopsies. A study from the Cleveland Clinic showed that when the clinical diagnoses were compared to the histologic diagnoses, the dermatologists were 75% accurate, while nondermatologist were only 40% accurate.21 Another study by Kitter et al showed diagnosing melanoma by the unaided eye was only 60% accurate.22