Skin Disorders

September 27, 2011

Skin disorders can be broadly categorized as either rashes or as growths. Rashes are often a result of skin inflammation and can be precipitated by a wide variety of causes. Two common inflammatory diagnoses in women are acne and atopic dermatitis, commonly called eczema. Growths or tumors may be further classified into benign, pre-malignant, or malignant lesions. The most common tumors are outlined in the following table.

Acne is a skin condition that is primarily a disease of adolescence but may persist through the third decade or beyond, particularly in women. Although the precise etiology of acne remains unknown, it is likely multifactorial. The almost universal presence of Propionobacterium acnes bacteria in the skin of patients with acne suggests it has a causative role. In addition, certain sex hormones (androgens) are known to regulate sebum or oil from the sebaceous glands and therefore play a role in the development of acne. The lesions of acne include pustules, red papules, and inflammatory nodules, which most commonly affect the face and to a lesser degree the back, chest, and shoulders. The physical appearance of acne can result in significant emotional distress to patients and is ample justification to treat this disorder. In addition, treatment may prevent the major sequelae of acne, namely, permanent and potentially disfiguring scars. Common treatment measures are aimed at decreasing the bacterial load, reducing the level of androgens, and decreasing sebum production.

Benign Premalignant Malignant
Seborrheic keratoses Actinic keratoses Basal cell carcinoma
Skin tags   Squamous cell carcinoma
    Malignant melanoma

Atopic dermatitis or eczema is an inflammatory condition of the skin that is typically a chronic and relapsing disorder, which usually starts in infancy and childhood, but may persist into adulthood. Persons with atopic dermatitis are often predisposed to other allergic diseases including hay fever and asthma. The cardinal features of atopic dermatitis are itchy, dry skin which when scratched or irritated can lead to a rash. Common locations for atopic dermatitis are around the eyes and in the creases of the elbows and knees. Many adults with atopic dermatitis may have chronic hand eczema as the only manifestation of their disease. The mainstays of treatment for atopic dermatitis include avoiding common skin irritants, keeping the skin well hydrated with emollients, topical steroid treatments, and control of itching with antihistamines.

Seborrheic keratoses are extremely common skin tumors, usually affecting people older than 50 years but also seen in young adults. These lesions usually arise on the trunk, face, and upper extremities and can range in color from tan to red or even black. Such skin changes can occur as an isolated lesion or hundreds may be present in the same person. Their diagnosis is often made based on a clinically “stuck-on” appearance. Seborrheic keratoses represent a benign proliferation of immature keratinocytes. The tendency for seborrheic keratoses may be inherited in an autosomal dominant fashion. No treatment is necessary for most lesions.

Skin tags are outgrowths of normal skin. Twenty-five percent of adults have skin tags, and there is a familial tendency for these lesions. They usually occur at sites of friction such as the axillae, neck, underneath the breasts, and in the groin area. Treatment is indicated only if lesions are irritating or the individual desires removal for cosmetic reasons.

Actinic keratoses are common premalignant lesions of the skin, resulting from chronic, cumulative sun exposure, and occurring most commonly in fair-skinned people on sun-exposed skin sites including the face and the dorsal hands. Actinic keratoses are characterized by an irregular shape, and scaly or “sandpaper” texture. If left untreated, some actinic keratoses may progress to become cancerous. Treatment options include liquid nitrogen or prescription medications aimed at destroying the premalignant cells.

Basal cell carcinoma is a malignancy of the basal cells in the epidermis. It is the most common human

malignancy with approximately 750,000 new cases in the United States each year. Basal cell carcinoma occurs more commonly in men, almost exclusively in whites, and most frequently between the ages of 40 and 80. Predisposing factors include chronic UV sunlight exposure, arsenic, and ionizing radiation. Basal cell cancers are usually noticed as a new growth in sun-damaged skin that is skin colored, sometimes pearly, and has a tendency to bleed. Most basal cell tumors spread locally and do not metastasize. Treatment usually involves surgical excision but is influenced by size and location of the tumor.

Squamous cell carcinomas are malignant tumors of keratinocytes, the main cell type that comprises the skin. Although squamous cell cancer is the second most frequent skin carcinoma, its incidence is increasing greatly. Although squamous cell cancer occurs most commonly in white men older than 55, women with extensive sun exposure or other predisposing factors are affected. Predisposing factors include: UV sunlight exposure, old burn scars, sites of chronic inflammation, radiation therapy, arsenic, immunosuppression, and smoking (lip lesions). A squamous cell carcinoma commonly appears as a new growth that may be scaly and has a tendency to bleed. These tumors can in some cases metastasize depending on the location of the tumor or the predisposing cause. Treatment typically involves excision of the lesion.

Melanoma, which exactly means black tumor, is the malignant proliferation of pigment-producing cells, called melanocytes. Malignant melanoma deserves all the attention given it because of its potentially fatal nature, rapidly increasing incidence, and excellent prognosis if treated early. Malignant melanoma represents 3% of all cancers, with tens of thousands of new cases in the United States annually. Representing 1-2% of all cancer-related deaths, the increase in the melanoma mortality rates is second only to lung cancer. Risk factors for developing malignant melanoma include fair hair and light eyes, extensive sun exposure, history of sunburns in childhood, multiple irregular moles, or a family history of melanoma. However, any patient with a history of change in a longstanding pig-mented lesion or a new lesion with suspect features should alert the clinician to the possible diagnosis of melanoma. A mnemonic to remember suspect features of melanoma is:

  • A = asymmetry
  • B = borders irregular and blurred
  • C = color change or variable pigmentation
  • D = diameter greater than 6 mm
  • E = elevation of previously flat lesion

Diagnosis is based on excisional biopsy and characteristic histologic findings. The depth of the tumor is of crucial importance in determining prognosis. With a thick melanoma, additional tests are required to evaluate possible metastasis to lymph nodes and other organs. Treatment of melanoma depends on the stage of the tumor: excisions are performed for thin lesion whereas thicker tumors may require adjuvant therapy.

See Also: Cancer, Dermatitis, Skin cancer, Skin care, Smoking

Suggested Reading

  • Freedberg, I., Eisen, A., Wolff, K., Austen, K. F., Goldsmith, L., Katz, S., et al. (Eds.). (1999). Fitzpatrick’s dermatology in general medicine (5th ed., pp. 769, 1464). New York: McGraw-Hill.
  • Goldstein, B. G., & Goldstein, A. O. (1997). Practical dermatology (2nd ed., pp. 128-157). St. Louis, MO: C. V. Mosby.

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