A 31-year-old woman is referred for evaluation of a mole on her left upper arm. She states that the lesion has been present for several years. The lesion has never bled but has grown in size over the past several months. She is fair skinned and admits to frequent sunburns since early childhood but has never used an indoor tanning bed and has no history of prior skin cancer. The physical examination reveals a 1.4cm pigmented lesion with a slightly elevated, darkened center.

A 65-year-old man of Mediterranean descent is referred by his primary care physician for evaluation of lesions affecting his feet and calves. The patient states the condition was first noted about 4 months ago and remained without symptoms until recently when 1 lesion began to bleed. His only treatment to date has been topical miconazole cream prescribed by a podiatrist for athlete’s foot. He is currently on medication for control of his hypertension. Physical examination reveals scattered violaceous patches and firm, dusky red papules.

An 81-year-old woman requests removal of a lesion on her left leg. She states that a growth had been removed from this site about 7 years ago and “grew back.” She was told that the pathology report for the lesion was “benign” and she denies a history or family history of skin cancer. Examination reveals a 1.5cm firm nodule with a faint bluish coloration and a central linear scar. No similar lesions are noted elsewhere.

An 18-year-old college student presents with a complaint of a skin condition that “comes and goes” several times a week. He noticed the first episode about a month ago. Each episode is accompanied by varying degrees of itchiness and lasts 1 to 3 hours. The patient is otherwise healthy and is taking no medications, has no history of food allergy, and does not take illicit drugs. Pressure with a pencil eraser resulted in a red, zig-zag appearance.

A 64-year-old woman presents with a request for the removal of a lesion on her right cheek. She first noticed the growth approximately 18 months ago, at which time she sought an evaluation. At the time the site was injected with triamcinolone. However, over the past 3 months she reports a marked increase in the lesion’s size. Upon manipulation, a whitish discharge was observed. Physical examination revealed a 1.8cm firm, flesh-colored nodule with 2 whitish papules within the medial border.

A 20-year-old woman is requesting evaluation of a mole on the sole of her left foot. The lesion had been present for several years and remained unchanged. She sought consultation after reading a newspaper article on melanoma. The patient’s personal and family history are negative for skin cancer. She has experienced frequent sunburns as a child as well as the occasional use of indoor tanning beds. Examination reveals an irregularly shaped hyperpigmented macule. Scattered nevi were noted elsewhere on her body.

A 12-year-old boy is referred for evaluation of a skin lesion located on his right inner thigh. The growth has been present for several months and has remained asymptomatic. The patient is in good health and has no similar lesions elsewhere on the body. The family history is negative for genodermatoses. Examination of the lesion reveals a reddened 1.0cm firm nodule.

A 23-year-old female medical student with a history of atopic dermatitis and acne vulgaris presents with a 2-week history of a progressive, dry, painful, itchy rash on the dorsal surface of both hands (Figure 1). The lesions are ill-defined with fissuring noted. The rash is not present anywhere else. She has been taking isotretinoin (50mg/d) for 2 months for acne treatment. She tried applying over-the-counter colloidal moisturizers with minimal improvement.

A 20-year-old college student presents with a rash on her arms and chest that has been present for the past 2 months. The condition initially responded to oral minocycline but after 4 weeks of therapy, the rash worsened. Additional topical clindamycin and a benzoyl peroxide wash did not improve the condition. The patient reports several areas have begun to itch. She is in good health and takes an oral contraceptive. Examination reveals multiple pustules and inflammatory papules of the affected areas.

A 44-year-old man presents requesting removal of a growth on his right hand. The lesion has been present for at least 6 months and was treated elsewhere with 2 courses of liquid nitrogen, which proved ineffectual. The patient has no pain at the site unless traumatized. He is in good health and denies history of systemic disease. Examination reveals a firm, fixed 1.8cm slightly pinkish nodule with a hyperpigmented rim. No similar lesions are noted elsewhere.

A 70-year-old man presents for removal of a “skin tag” about his umbilicus. He is accompanied by his wife who noted the lesion 3 days ago. The family lives in northeastern Pennsylvania, owns several cats, and walks daily in a wooded area. The patient denies new rash, fever, headache, and joint pains.

A moderately obese 12-year-old adolescent presents with pruritic bumps under both arms. The condition has been present for several months and has not responded to topical antifungal creams or antiperspirants. She denies a family history of a similar problem and is otherwise in good health. Examination reveals multiple 1 to 3mm papules ranging in coloration from white to dark brown. Several of the larger papules have keratotic plugs.

A 24-year-old woman presents with a spreading rash on her arms. A single patch first appeared ~2 weeks ago. The patient reports that the rash was somewhat itchy and continued to enlarge despite application of 1% hydrocortisone. Subsequently, new patches arose on both arms. The patient exercises at a local gym at least 3 days each week and is in good health. Examination reveals multiple erythematous patches with crusting. Removal of a crust by curettage revealed slight purulence.

A woman in her early 40s is seeking evaluation of a pink-brown papule located on a brown plaque in the right inframammary area. The patient is 4 months pregnant. Although the lesion has been a longstanding concern, the patient has observed an increase in prominence of the papule over the past 6 months.

A 64-year-old woman with stable hypothyroidism presents to the clinic after experiencing sudden hair loss 2 weeks following COVID-19 infection that was confirmed by a positive COVID-19 rapid antigen test. She had no prior history of hair loss and denies starting new medications, recent illnesses, or psychosocial stressors. The scalp shows enlarging circumscribed patches of nonscarring alopecia. Other findings included pitting on multiple fingernails. Laboratory blood work was normal, including complete blood counts, electrolytes, antinuclear antibodies, erythrocyte sedimentation rate, C-reactive protein, dehydroepiandrosterone-S, and thyroid stimulating hormone.

A 31-year-old Hispanic woman presents for treatment of an itchy rash on her back. The condition has been present for several months and has not responded to topical steroids or over-the-counter antihistamine creams. The patient is moderately obese and takes metformin for recently diagnosed diabetes. Physical examination reveals a well-circumscribed hyperpigmented patch on her upper back. No similar findings are noted elsewhere on the body.

A 40-year-old woman presents for evaluation of a skin growth on her chest, which she first noticed approximately 4 weeks ago. The patient has a history of ample sun exposure and a family history of skin cancer. According to the patient, the lesion has remained asymptomatic. Physical examination reveals a 0.6cm firm, erythematous papule. Scattered nevi and lentigos are noted elsewhere on the body.

A 10-year-old boy is referred for evaluation of a white spot on his scalp. According to his mother, the spot was first noted about 6 weeks ago and has not changed since the initial observation. The patient denies antecedent trauma. Family history is positive for melanoma (paternal grandmother). Upon examination, a well-circumscribed depigmented macule with a slightly elevated central brownish papule is observed. Additionally, a darker papule is noted at the periphery.

A 37-year-old woman developed a rash on her chest ~6 weeks ago. A primary care physician diagnosed the rash as a yeast infection, which has been treated with clotrimazole cream without resolution. The patient is in good health and takes no medications, she has a history of eczema as a child. She notes that the rash is occasionally pruritic. Examination reveals scattered papules in a linear distribution on her chest. No similar lesions are noted elsewhere on the body.

A 68-year-old man requests removal of a lesion on his left forearm. He states that the growth began as a “pimple” about 5 to 6 weeks ago and has rapidly increased in size. The lesion has not bled but he experiences tenderness when pressure is applied to the site. The patient has a history of actinic keratoses of his face and scalp, which have been treated with either cryosurgery or topical fluorouracil cream. Examination reveals a 3.5cm pinkish nodule. Surface crusting is readily removed with an alcohol swab.

A 29-year-old woman requests an evaluation of a rash affecting her neck and upper chest that developed ~15 years ago. The rash was recently treated with a prescription topical steroid without improvement. She reports that the rash is not itchy or symptomatic but she is most concerned about its cosmetic appearance. Her father and other siblings have a similar rash. Examination reveals multiple hyperkeratotic brown papules.

A 41-year-old woman presents with painful lesions on her calves and ankles that first appeared 2 months ago. The patient reports the lesions have diminished in size following treatment with triamcinolone. Her history includes Graves disease, Sjogren’s syndrome, and rheumatoid arthritis; she is taking multiple medications. Most recently, she completed a course of teprotumumab for severe thyroid eye disease. Physical examination reveals multiple firm erythematous nodules, which are painful on palpation.

A 58-year-old man is referred for evaluation and treatment of skin lesions. The lesions have been present for several months and he has been treated for scabies on 3 separate occasions. No other family members are affected. He is currently taking oral medications to control hypertension and gout and denies any history of anxiety or mental health issues. Initially, he denies picking or scratching at the sites but later in the interview admitted to doing so. Upon examination, scattered erythematous, firm nodules with excoriations are observed on his upper back and arms.

An 11-month-old baby is brought in for evaluation of a rash on her extremities, face, and trunk that was first noted by her parents ~1 week ago. They relate that the child is otherwise in good health, has remained without fever, and is not scratching. Neither parent nor an older sibling complained of a similar rash or itch. Examination reveals multiple nonexcoriated flesh-colored to hyperpigmented 1 to 3mm papules on affected areas. No lymphadenopathy or oral lesions are noted. The palms and soles are uninvolved.