SKs have a wide range of appearances and can occur anywhere on the body. They are primarily distributed on the face, chest, back, and arms. The color of SKs can range from tan to dark brown or even black, which can mimic the appearance of melanoma. The most common history and presentation is a slowgrowing, waxy, and rough-textured plaque that crumbles. Older generations often referred to them as “barnacles” as they can sometimes be scraped off. In the early stages of development, the lesion may be small and smooth, whereas in the later stages, SKs may become elevated, enlarged, and darker in color. Some have a wart-like appearance due to the presence of keratin that deposits, called horny pearls or pseudocysts. Typically, SKs are asymptomatic but can become extremely pruritic and irritated, especially in areas of friction such as the inframammary folds or the bra area.

Due to the variety of clinical presentations, it can be difficult to differentiate an SK from a benign wart or malignant nodular melanoma. Therefore, careful examination of SKs is important so that benign lesions are not unnecessarily biopsied and possible malignant neoplasms are not overlooked. In some rare cases, melanoma can arise in an established SK. The patient may report a new onset of itching, bleeding, pain, or color changes, which should not be disregarded even if the lesion has been present for years.

It can be helpful to use an otoscope or dermatoscope to gain a closer visual examination of the lesion. Subtypes of SKs can have classic features that provide diagnostic clues (Figure 11-1).

SKs are benign and do not require treatment. Patients may request treatment for cosmetic reasons or for symptomatic relief from pruritus, irritation, or tenderness. The preferred method is cryotherapy for smaller and thinner lesions. Patients should be warned that SKs may need more than one treatment and can recur. Care must be taken as aggressive cryotherapy may result in hypopigmentation or scar that can appear more disfiguring than the SK. Thicker or larger SKs may be handled more easily with shave excision. Ammonium lactate and α-hydroxy acids have been shown to reduce the appearance of SKs.

SK can be disfiguring, especially if they involve the face or large and dark lesions. Their appearance can make individuals self-conscious, lower their self-esteem, and be perceived as a sign of aging. Complications occur if a malignancy is missed or treatment is overly overaggressive. Patients who “pick” at their lesions may develop secondary infections.

The Leser-Trélat sign is a rare but sudden eruption of numerous SKs that precedes, accompanies, or follows an underlying malignancy (Figure 11-2). There is no evidence to support this phenomenon, yet most clinicians consider it to be a reliable indicator. Until definitive data can support or reject Leser-Trélat, primary care providers should ensure that the patient has completed age-appropriate screening examinations and other diagnostics indicated from the patient history and physical.

SHs usually present as soft, yellowish, 2- to 3-mm papules occurring as single or multiple lesions on the face (predominately nose, cheeks, and forehead). Lesions have a central dell (umbilication) surrounded by “crown vessels” (Figure 11-3). The vessels occur in an organized manner on the outer rim and not in the dell. This is compared to the erratic pattern blood vessel usually found across the center of a basal cell carcinoma. The lesions are soft to palpation in contrast to basal cell carcinoma, which tends to be firmer with erratic pattern of telangiectasia across the central area. Some individuals state that they express the lesion’s contents upon squeezing.

In most cases, SHs do not need to be treated. If they are widespread, disfiguring, or diffuse, several therapies may be implemented. It is important to note that the lesions will frequently recur after discontinuation of therapy. Isotretinoin should only be used by experienced dermatology practitioners who are knowledgeable about the medication and registered with iPLEDGE, the federally monitored information and restricted distribution program. Phototherapy (with combined use of 5-aminolevulinic acid or PUVA) can be helpful in some cases. All of the above treatments are considered off label and will not likely be covered by health insurance.

A wide variety of destructive agents may be utilized, including phototherapy, laser treatment, cryotherapy, cauterization or electrodesiccation, topical chemical treatments (bichloracetic acid or trichloroacetic acid), and shave excision. Destruction of SHs may result in atrophic or ice pick scarring or changes in pigmentation (transient or permanent) that may be less desirable than the original lesion.

Syringomas present as flesh-colored, translucent, or yellow papules. There are several subtypes, but most are small (often 1-3 mm) papules located on the eyelids, axilla, umbilicus, or vulva. Syringomas are more common in women and have an onset around puberty (Figure 11-4). Most are asymptomatic, but patients may report pruritus. Patients can be distressed by their appearance and seek treatment for cosmesis.

Treatment is not necessary for these benign tumors. If requested for cosmetic enhancement, modalities to treat syringomas may include scissor excision, electrodesiccation, electrocautery, laser, cryotherapy, trichloroacetic acid, dermabrasion, topical retinoids, and oral isotretinoin (not FDA approved). The size, location, and number will influence the type of modality employed.

Clinicians should heed a word of caution if attempting to treat syringomas prominently located on the patient’s face, often close to the lid margin. Remember, if the syringoma is visibly obvious, so will any resulting scar, abnormal pigmentation, or complication that results from your treatment. As always, an experienced clinician in the procedure should perform treatment of benign lesions for cosmetic purposes. Preauthorization for the procedure with the patient’s insurance company is advised as coverage for the procedure varies significantly.

Syringomas are benign, but in rare instances, they are associated with Brooke-Spiegler syndrome and Down syndrome. Syringomas of the scalp can produce scarring alopecia. These lesions may affect self-esteem and body image, especially at puberty.

Skin tags are small, soft, pedunculated (atop an elongated stalk) papules that favor the skin folds. They are commonly located in areas of friction including the neckline, axilla, inframammary and inguinal
folds, and eyelids. They may be hyperpigmented or flesh color and vary in size from 1 to 8 mm. Secondary changes include inflammation, hemorrhagic crust from trauma or friction, and necrosis from torsion (Figure 11-5).

The diagnosis of skin tags is a clinical one. Biopsy may be indicated if there are any suspicious features. Additionally, if multiple tags are present, a thorough history and physical should be performed to rule out any underlying metabolic abnormalities. Practitioners excising skin tags should be cautioned against discarding the tissue (skin tag) without sending it to pathology. While it may be an additional cost to the patient, the clinician should ensure that they have not overlooked a malignancy.

Skin tags do not require treatment but can be removed if pruritic, painful, or irritated. Management modalities include electrodesiccation, scissor excision (clipping), ligation, and cryotherapy (Figure 11-6). Over-the-counter products containing salicylic, retinoic, or carbolic acid, coal tar, and “natural” ingredients are available. Popular do-it-yourself products promoted on the internet and television entice patients to use homeopathic or “quick” fixes for patients tired of living with these ugly lesions. Ligation of a skin tag, by tying it at the base with string or dental floss, is an old-fashioned remedy. Patients sometimes use an abrasive tool or body scrub to exfoliate the papules when they are small. Brave patients tired of the lesions have been known to use nail clippers or scissors and cut them off themselves. Often these treatments result in only partial resolution, severely inflamed lesions, or secondary infections, which prompts the patient to visit your office for complete resolution.

Although they are benign, skin tags can become symptomatic, including irritation, pain, and bleeding usually from clothing, jewelry, or necklace. Torsion sometimes occurs and results in necrosis, with the papule turning black and falling off. Most importantly, misdiagnosis of a skin tag could be melanoma and basal cell carcinoma.

Fibrous papules are firm, dome-shaped papules that usually occur on the lower portion of the nose and occasionally on other areas of the face (Figure 11-7). They are almost always a solitary lesion but occasionally present as multiple papules on the face. Fibrous papules are flesh, red, or pink color and may have hair protruding from the lesion. Clinically, they can be difficult to differentiate from an early basal cell carcinoma. Multiple fibrous papules or angiofibromas in a butterfly distribution of the face may be a clinical manifestation of tuberous sclerosis and prompt further evaluation.

Treatment is not necessary for these fibrous papules, but may be performed for symptomatic or cosmetic reasons. Curettage or shave removal can be considered, but may result in a scar and the lesion may recur. Excision may also be performed and has better cosmesis and less likelihood of recurrence.

If treated, patients should be advised regarding scars and recurrence.

In adults, solitary neurofibromas are soft fleshy papules that are usually flesh color to pinkish white. They can vary in size from a few millimeters to centimeters (Figure 11-8). Button-holing may be present (pressure with your finger may invaginate the lesion). Multiple neurofibromas presented in childhood should be evaluated for neurofibromatosis (Figure 11-9).

When one or two lesions are present, they are usually spontaneous lesions without systemic significance. Treatment may be considered if a neurofibroma is symptomatic or is cosmetically undesirable. Surgical excision and CO₂ laser may yield the best results. Shave excisions can leave large scars and a higher risk for recurrence.

Rarely, neurofibromas may cause itching or pain. Isolated lesions are not a cause for concern if no other abnormalities are found.