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The content that appears below is from Fitzpatrick’s Dermatology Flashcards.
Acanthosis nigricans is a cutaneous marker related to endocrine disorders (particularly diabetes), drug administration, and malignancy; there is insidious onset, which in malignancy is rapid.
Type 1: Hereditary benign has no associated endocrine disorder. Type 2: Benign has insulin-resistant endocrine disorders (insulin-resistant type II diabetes mellitus, hyperandrogenic states, acromegaly/gigantism, Cushing disease, hypogonadal syndromes, Addison disease, and hypothyroidism). Type 3: Pseudo is associated with obesity, and more common in patients with darker pigmentation and metabolic syndrome. Obesity produces insulin resistance. Type 4: Drug-induced may be caused by nicotinic acid in high dosage, stilbestrol in young males, glucocorticoid therapy, diethylstilbestrol/oral contraceptive, and growth hormone therapy. Type 5: Malignant is caused by neoplastic disease, usually adenocarcinoma of gastrointestinal or genitourinary tract; less commonly, bronchial carcinoma, or lymphoma.
Darkening of pigmentation; skin appears dirty and thickens, appearing velvety with accentuated skin lines. The surface becomes rugose and mammillated. In Type 3 there is a velvety patch on inner, upper thigh at site of chafing and often skin tags in body folds and the neck. Type 5 has hyperkeratosis and hyperpigmentation, and there is involvement of oral mucosa and the vermilion border of lips. Hyperkeratosis of palms/soles, with accentuation of papillary markings (“tripe hands”), and involvement of oral mucosa and vermilion border of lips occur. Most commonly lesions are on the axillae, neck, groin, anogenitalia, antecubital fossae, knuckles, submammary area, and umbilicus. In type 5 the periocular, perioral, mammillar areas, and palms are also affected. The oral mucosa has a velvety texture with delicate furrows, and in type 5, the mucocutaneous junctions are commonly involved.
Diagnosis is clinical and the differential includes reticulated papillomatosis (Gougerot-Carteaud syndrome), pityriasis versicolor, X-linked ichthyosis, retention hyperkeratosis, and nicotinic acid ingestion.
Treat associated disorder. Topical keratolytic and/or topical or systemic retinoids may improve skin lesions but are not very effective.
Occurs commonly, affecting approximately 85% of young people and typically begins in puberty, though it may appear first at 25 years or older. Acne is more severe in men than in women and has a lower incidence is those of Asian and African descent. There is a multifactorial genetic background and familial predisposition. Most individuals with cystic acne have parent(s) with a history of severe acne.
Lesions may be painful (especially the nodulocystic type) and last weeks to months and are often worse in fall and winter. Lesions occur on the face, neck, trunk, upper arms, and buttocks.
Comedones: open (blackheads) or closed (whiteheads); comedonal acne. Papules and papulopustules: a papule topped by a pustule; papulopustular acne. Nodules or cysts: 1–4 cm in diameter; nodulocystic acne: soft nodules result from repeated follicular ruptures and reencapsulations with inflammation, abscess formation (cysts), and foreign-body reaction.
Comedones are required for diagnosis of any type of acne and are not a feature of acne-like conditions or the following conditions: Face: S. aureus folliculitis, pseudofolliculitis barbae, rosacea, and perioral dermatitis. Trunk: Malassezia folliculitis, “hot-tub” pseudomonas folliculitis, and S. aureus folliculitis.
Mild acne Use topical antibiotics (clindamycin and erythromycin) and benzoyl peroxide gels (2%, 5%, or 10%). Topical retinoids may be used with detailed instructions for gradual increases of 0.01% to 0.025% to 0.05% cream/gel or liquid and combination with benzoyl peroxide–erythromycin gels. Extraction is not helpful unless properly done after pretreatment with topical retinoids. Moderate acne Add oral antibiotics to the above regimen. Minocycline is most effective, 50–100 mg twice daily, or doxycycline, 50–100 mg twice daily, tapered to 50- mg/d as acne lessens. Use of oral isotretinoin to prevent scarring is effective. Severe acne Add systemic treatment with isotretinoin for cystic or conglobate acne or for any other acne refractory to treatment.
Occurs commonly, affecting approximately 85% of young people and typically begins in puberty, though it may appear first at 25 years or older. Acne is more severe in men than in women and has a lower incidence in those of Asian and African descent. There is a multifactorial genetic background and familial predisposition. Most individuals with cystic acne have parent(s) with a history of severe acne.
Comedones are required for diagnosis of any type of acne and are not a feature of acne-like conditions or the following conditions: Face: S. aureus folliculitis, pseudofolliculitis barbae, rosacea, perioral dermatitis. Trunk: Malassezia folliculitis, “hot-tub” pseudomonas folliculitis, S. aureus folliculitis.
Use topical antibiotics (clindamycin and erythromycin) and benzoyl peroxide gels (2%, 5%, or 10%). Topical retinoids may be used with detailed instructions for gradual increases of 0.01% to 0.025% to 0.05% cream/gel or liquid and combination with benzoyl peroxide–erythromycin gels. Extraction is not helpful unless properly done after pretreatment with topical retinoids.
Add oral antibiotics to the above regimen. Minocycline is the most effective, 50–100 mg twice daily, or doxycycline, 50–100 mg twice daily, tapered to 50- mg/d as acne lessens. Use of oral isotretinoin to prevent scarring is effective.
Add systemic treatment with isotretinoin for cystic or conglobate acne or for any other acne refractory to treatment.
Acquired nevomlanocyctic nevi, also called moles, are one of the most common acquired growths in light-skinned people, and also occur in darker skinned individuals, though less commonly. Most adults have 20 or more moles; melanoma risk is related to the number of moles.
Nevi appear in early childhood and usually reach a maximum in young adulthood even though some arise in adulthood. Later there is a gradual involution and fibrosis of lesions, and most disappear after age 60. Lesions are asymptomatic but they may itch when they grow; this is not a sign of malignancy per se, but does warrant regular follow-up.
Nevi may be macules or papules <1 cm in diameter with a uniform tan, brown, or black color or nonpigmented, and may contain telangiectasia and hair follicles. They are round/oval/dome-shaped with smooth regular borders. The surface may be smooth or cobblestone-like, firm, or soft, and sometimes papillomatous or hyperkeratotic. Nevi occur in random distributions on the face, trunk, extremities, and scalp.
Diagnosis clinical and, as for all pigmented lesions, the ABCDE rule applies: Asymmetry, Borders irregular, Color not uniform, Diameter is large, Elevation or Enlargement. If any of the ABCDE characteristics are present, use dermoscopy and/or histology to rule out malignancy. The differential includes solar lentigos, atypical nevi, lentigo maligna, seborrheic keratosis, melanoma, basal cell carcinoma, dermatofibroma, Spitz nevi, blue nevi, neurofibroma, trichoepithelimoa and sebaceous hyperplasia.
Surgical removal is only necessary if nevi occur in certain regions (scalp, mucous membranes, anogenital region), or if nevi undergo a rapid change in size, become variegated in color, have irregular borders, become eroded without trauma, or itch, hurt, or bleed. Dermoscopy is recommended if any criteria for melanoma or dysplastic nevi occur. Manipulation or traumas do not cause malignancy. Send excised nevi for histologic diagnosis to rule out congenital, dysplastic, blue nevi, and melanoma. Removal via electrocautery should only be considered if nevi can be unequivocally diagnosed as benign.
Moles are very common, small (<1 cm), circumscribed, acquired pigmented macules, papules, or nodules composed of melanocytic nevus cells located in the epidermis, dermis, and, rarely, subcutaneous tissue. While moles are benign, the risk of melanoma is related to the number of them present. Melanocytic nevi evolve from the epidermis and involute to the dermis where they gradually disappear.
Moles are asymptomatic and classified as junctional, compound, or dermal melanocytic depending on where they arise and the state of evolution.
Junctional nevi arise at the dermal–epidermal junction, compound melanocytic nevi invade the dermis, and dermal melanocytic nevi are fully involuted into the dermis.
Junctional moles are round or oval macules, or only very slightly raised papules. Compound moles are dome-shaped, sometimes with a cobblestone-like surface, papillomous, or hyperkeratotic. Dermal moles are round or dome-shaped well-defined papules or nodules. Junctional and compound moles are uniform tan, brown, dark brown, or even black with smooth, regular borders, and are discrete and scattered. Dermal moles are skin-colored, tan, or flecked with brown. Moles are never >1 cm in diameter.
Diagnosis is made clinically and the most important thing is to rule out melanoma precursors and melanoma using the ABCDE (asymmetric, uneven borders, color mixed, large diameter, and evolving). The differential includes solar lentigo, flat atypical nevus, lentigo maligna, other raised pigmented lesions, seborrheic keratosis, small superficial spreading melanoma, early nodular melanoma, pigmented basal cell carcinoma, dermatofibroma, Spitz nevus, blue nevus, neurofibroma, trichoepithelioma, dermatofibroma, and sebaceous hyperplasia.
Rule out melanoma precursors and melanoma, and in cases of doubt, use dermoscopy, biopsy, or excision with a narrow margin.
Acrodermatitis enteropathica is an autosomal recessive disorder of zinc absorption occurring in infants, bottle-fed with bovine milk or in breast-fed infants, soon after weaning.
Children with acrodermatitis enteropathica whine and cry constantly and exhibit photophobia and growth failure. Anemia, low serum/plasma zinc levels, and reduced urinary zinc excretion are seen.
Patches and plaques of dry, scaly, sharply marginated and brightly red, eczematous dermatitis evolve into vesiculobullous, pustular, erosive, and crusted lesions. Initially lesions are in the perioral and anogenital areas and later on the scalp, hands and feet, flexural regions, and trunk. Fingertips are glistening, erythematous, with fissures and secondary paronychia. Lesions become secondarily infected with Candida albicans and S. aureus and there is impaired wound healing. Diffuse alopecia and graying of hair occur and there is paronychia, nail ridging, and loss of nails. In the oral cavity, there may be a red, glossy tongue and superficial aphthous-like erosions.
Diagnosis is made on the basis of clinical and laboratory findings.
Dietary or IV supplementation with zinc salts in 2 to 3 times the required daily amount restores normal zinc status in days to weeks. After zinc replacement, severely infected and erosive skin lesions heal within 1–2 weeks. Diarrhea ceases and irritability and depression of mood improve within 24 hours.
Prolonged and repeated solar exposure leads to cumulative damage to keratinocytes by ultraviolet radiation, principally, if not exclusively, UVB (290–320 nm). Onset is usually in middle age and is more common in those who spend significant time outdoors. Actinic keratosis is frequent in light-skinned individuals, and rare in those with darker skin. Men are affected more commonly.
Lesions may be tender and develop over months to years. Patients wince upon excoriation.
Lesions are single or multiple, discrete, dry, rough, adherent, and scaly macules or papules on sun-exposed areas, usually on a background of dermatoheliosis. Removal of scales is painful and difficult. Lesions are skin-colored, yellow-brown, or brown, and often there is a reddish tinge. The roughness of the lesion makes it “better felt than seen.” Most commonly lesions are <1 cm and oval or round.
Diagnosis is clinical, confirmed with dermatopathology. Differential includes chronic cutaneous lupus erythematosus; seborrheic keratosis, flat warts, squamous cell carcinoma, and superficial basal cell carcinoma.
Actinic keratoses may disappear spontaneously, but generally last for years and can progress to squamous cell carcinoma. Further occurrences should be prevented by use of UVB/UVA sunscreen applied daily.
5-Fluorouracil (5-FU) cream, 5%, applied twice daily for 2–4 weeks or longer is effective, but causes significant erythema and erosions. Efficacy is increased and duration of treatment can be shortened if applied under occlusion and/or combined with topical tretinoin. However, this leads to confluent erosions and may require hospitalization. Reepithelialization occurs after treatment is discontinued. Pretreatment with light cryosurgery may improve efficacy. Imiquimod, given twice weekly for 16 weeks, also leads to irritation and erosions but is highly effective. Topical retinoids are effective for prevention and treatment of dermatoheliosis and superficial actinic keratose as is diclofenac gel, though the latter is irritating.
Cryotherapy via light spray or with cotton-tipped applicator is effective, especially combined with topical retinoids. Facial peels or facial resurfacing are effective for widespread lesions. Laser surgery is usually effective for individual lesions. Photodynamic therapy is effective though painful and cumbersome.
Lesions are single or multiple, discrete, dry, rough, adherent, and scaly macules or papules on sun-exposed areas, usually on a background of dermatoheliosis. Removal of scales is painful and difficult. Lesions are skin-colored, yellow-brown, or brown, and often there is a reddish tinge. The roughness of the lesion makes it “better felt than seen”. Most commonly lesions are <1 cm and oval or round.
5-Fluorouracil (5-FU) cream 5% applied twice daily for 2–4 weeks or longer is effective, but causes significant erythema and erosions. Efficacy is increased and duration of treatment can be shortened if applied under occlusion and/or combined with topical tretinoin. However, this leads to confluent erosions and may require hospitalization. Reepithelialization occurs after treatment is discontinued. Pretreatment with light cryosurgery may improve efficacy. Imiquimod, given twice weekly for 16 weeks, also leads to irritation and erosions but is highly effective. Topical retinoids are effective for prevention and treatment of dermatoheliosis and superficial actinic keratoses as is diclofenac gel, though the latter is irritating.
Cryotherapy, light spray or with cotton-tipped applicators, is effective, especially combined with topical retinoids. Facial peels or facial resurfacing is effective for widespread lesions. Laser surgery is usually effective for individual lesions. Photodynamic therapy is effective though painful and cumbersome.
Acute necrotizing ulcerative gingivitis is an infection of the oropharyngeal cavity. Risk factors include poor oral hygiene, HIV/AIDS, immunosuppression, alcohol and tobacco use, and nutritional deficiency.
There are punched-out ulcers of the interdental papillae, gingival hemorrhage, severe pain, foul odor/halitosis, fever, lymphadenopathy, and alveolar bone destruction.
Diagnosis is clinical and the differential includes malignancies, infections, and trauma.
Give systemic antibiotics such as clindamycin, metronidazole, or amoxicillin and instruct patients to follow good dental hygiene.
ACD is an eczematous (papules, vesicles) systemic disease defined by hapten-specific T cell–mediated inflammation after contact with a substance to which an individual was sensitized; sensitization can occur weeks to months/years after exposure. Sensitized T cells target the specific allergen, wherever it may come into contact with skin, making all skin hypersensitive to the allergen.
Eruption starts two or more days after contact. Repeated exposures lead to crescendo reaction. Intense pruritus, stinging, and pain may occur. In severe reactions, there may be fever.
Acutely, well-demarcated, erythematous, and edematous lesions occur with superimposed closely spaced papules and nonumbilicated vesicles. There may be bullae, confluent erosions, and crusts. In subacute cases, plaques of mild erythema occur with small, dry scales, and sometimes small, red, pointed or rounded, erythematous, firm papules and scales. In chronic cases, lichenified plaques occur with satellite, small, firm, rounded or flat-topped papules, excoriations, and pigmentation. Initially, lesions are confined to areas of contact and are often linear, with artificial patterns (“outside job”). Later, lesions may spread.
Diagnosis is made by history and clinical exam. Histopathology may be helpful, as is verification of the allergen by patch test. Exclude irritant contact dermatitis, atopic dermatitis, seborrheic dermatitis (face), psoriasis (palms and soles), epidermal dermatophytosis (KOH), fixed drug eruption, erysipelas, and phytophotodermatitis.
Identify and remove the allergen, and advise patients on preventing further exposure. Drain larger vesicles but do not remove tops. Use wet dressings with cloths soaked in Burow’s solution and changed every 2–3 hours. Use topical glucocorticoid ointments/gels (classes I–III) and appropriate skin lubricants.
ACD is an eczematous (papules, vesicles, pruritis) systemic disease defined by hapten-specific T cell–mediated inflammation after contact with a substance to which an individual was sensitized; sensitization can occur weeks to months/years after exposure. Sensitized T cells target the specific allergen presented making all skin hypersensitive to the allergen.
Identify and remove the allergen, and advise patients to prevent further exposure. Drain larger vesicles but do not remove tops. Use wet dressings with cloths soaked in Burow’s solution and changed every 2–3 hours. Use topical glucocorticoid ointments/gels (classes I–III) and appropriate skin lubricants.
Allergic phytodermatitis occurs in sensitized individuals after exposure to a wide variety of plant allergens and is characterized by an acute, very pruritic, eczematous dermatitis, often in a linear arrangement. In contrast, phytophotodermatitis is a photosensitivity reaction occurring in any individual with a photosensitizing plant–derived chemical on the skin and subsequent sun exposure. Some of the most common plant allergens are poison ivy (Toxicodendron radicans), poison oak (T. querifolium, T. diversilobum), and poison sumac (T. vernix). Some others are Brazilian pepper, cashew tree, ginkgo tree, Indian marker tree, lacquer tree, mango tree, and rengas tree.
Pruritis is mild to severe and often sensed prior to any detectable skin changes; some patients experience pain. There is a history of contact with plants or with foods and other products containing the allergens.
Initially, there are well-demarcated patches of erythema, characteristic linear lesions that may progress to papules and edematous plaques resembling cellulitis. These may be severe, especially on face and/or genitals. Microvesiculation, bullae, erosions, and crusts may be present. Postinflammatory hyper-pigmentation commonly occurs in darker skinned individuals.
Diagnosis is clinical based on history and skin findings. The differential includes contact dermatitis (non-plant allergen), phytophotodermatitis, soft-tissue infection (cellulitis, erysipelas), atopic dermatitis, inflammatory dermatophytosis, early herpes zoster, and fixed drug eruption.
Topical glucocorticoids provide relief of pruritus; wet dressings may be helpful for large lesions. Consider systemic glucocorticoids if pruritis prevents the patient from sleeping or functioning. Advise patients to avoid the allergen or to wash exposed areas with soap and water as quickly as possible after inadvertent contact.
Alopecia areata is the localized loss of hair in round or oval areas with no apparent inflammation of the skin. It is nonscarring and leaves the hair follicle intact, so regrowth is possible. Alopecia areata may be associated with autoimmune diseases. Age of onset is in early adulthood, though it can occur at any age.
Hair loss is gradual and patches of hair loss can be stable and often show spontaneous regrowth over a period of several months; new patches may appear while others resolve. Patients are usually very concerned about hair loss and potential for continued, progressive balding. There may be minimal erythema in area of hair loss.
“Exclamation mark” hairs are seen at the margins of hair loss areas and are diagnostic. These are broken-off stubby hairs (distal ends are broader than proximal ends). Alopecia may occur in scattered discrete areas or be confluent with total loss of scalp hair, or generalized loss of body hair (including vellus hair). Diffuse alopecia areata of scalp gives the appearance of thinned hair and can be difficult to differentiate from pattern hair loss of telogen effluvium, or hair loss with thyroid disease. As the hair regrows, new hairs are fine, often white or gray.
Diagnosis is clinical with laboratory findings used to rule out lupus, syphilis, and tinea capitis. The differential includes white-patch tinea capitis, trichotillomania, early scarring alopecia, pattern hair loss, and secondary syphilis (alopecia areolaris) (“moth-eaten” appearance in beard or scalp).
Treatment is directed at inflammatory infiltrate and growth inhibitor factors produced by inflammation, though no curative treatment is currently available. In many cases, the most important factor in management of the patient is psychological support from the dermatologist, family, and support groups. Topical glucocorticoids are usually not effective, though intralesional glucocorticoids are very effective temporarily and systemic glucocorticoids may induce regrowth, but this is temporary and the drug has long-term risks.
Anagen effluvium is the diffuse, extensive loss of hair due to chemotherapy with alkylating agents, toxicity, or protein malnutrition. Onset is usually rapid and extensive after any insult to hair follicle that impairs its mitotic/metabolic activity. Severity is generally dose dependent.
The skin is unaffected. Hair loss is diffuse and extensive with hair breaking off at the level of the scalp. Eyebrows, eyelashes, facial, and body hair may also be affected, and the nails show transverse bands or ridging (Beau lines).
Diagnosis is clinical, based on where the breakage is and the patient history. The differential includes alopecia, telogen effluvium, tinea capitis, and trichotillomania.
No effective preventive measures are available as long as the toxic agents are present. Hair regrows after discontinuation of chemotherapy or other toxic agents, or adequate protein intake. Regrowth after radiation depends on type, depth, and dose fractionation, and may result in irreversible hair follicle stem cell damage.
While the term angio (“blood vessel”) keratoma implies a vascular tumor with keratotic elements, an angiokeratoma is actually an epidermal tumor into which capillaries and postcapillary venules are packed leading to hyperkeratosis.
Angiokeratomas are dark violaceous to black, often keratotic papules or small plaques that are hard upon palpation and cannot be compressed by diascopy. They may be solitary lesion (solitary angiokeratoma) or multiple. Angiokeratoma of Fordyce are multiple lesions in large numbers on the scrotum or vulva. Angiokeratoma of Mibelli comprise pink to dark red and even black papules on the elbows, knees, and dorsa of the hands. This autosomal dominant disease is rare and occurs in young women. Fabry disease (shown in the illustration) is an X-linked recessive disease and an inborn error of metabolism. Deficiency of α-galactosidase A leads to an accumulation of glycosphingolipids in the dermis, heart, kidneys, and autonomic nervous system. In this variant, the angiokeratomas are numerous, dark red, punctate, and tiny (<1 mm), located on the lower half of the body: lower abdomen, genitalia, and buttocks, although lesions may also occur on the lips. The homozygous males have also symptoms related to involvement of other organ systems: acroparesthesias, excruciating pain, transient ischemic attacks, and myocardial infarction. Heterozygous females may have corneal opacities. Fabry disease is very rare.
Diagnosis is clinical in most cases, and confirmed with biopsy when used to rule out malignant tumors. Fabry disease is diagnosed by family history and genetic testing. The differential includes purpura, petechiae, and other metabolic disorders; when lesions are solitary, the most important differential diagnosis is a small nodular or superficial spreading melanoma.
No treatment is needed for most angiokeratomas; laser surgery, liquid nitrogen, and electrocoagulation are options when treatment is needed.
Angiosarcoma is a rare, highly malignant proliferation of endothelial cells.
Lesions are purpuric macules and/or papules and nodules that bright red or violaceous and even black or solid nodules are solid that bleed easily, and ulcerate. Lesions occur in normal skin, usually on the scalp and upper forehead or in localized lymphedema, for instance in postmastectomy lymphedema (Stuart-Treves syndrome) or postirradiation lymphedema.
Diagnosis is made clinically and confirmed by biopsy. The differential includes other vascular lesions, Kaposi sarcoma, pyogenic granuloma, and lymphoma.
Treatment is excision with wide margins and chemotherapy (liposomal doxorubicin or paclitaxel); however, even with treatment, the 5-year survival is just above 10%.
Angular cheilitis is associated with increased moisture at commissures including nighttime salivation. Predisposing factors include thumb sucking in children, sagging face and loss of teeth in older persons, candidiasis in immunocompromised persons, S. aureus in atopic dermatitis, and isotretinoin treatment.
There is erythema and maceration at commissures and, if secondarily infected with Candida spp., a white plaque.
Direct microscopy with potassium hydroxide or culture will identify the source of the infection.
Identify and treat causes with appropriate antimicrobials.
(Courtesy of Dr. Nathaniel Treister.)
Atherosclerosis is associated with a spectrum of skin findings and affects 5% of men >50 years old; 10% of those develop critical limb ischemia. Risk factors are hyperlipidemia, hypercholesterolemia, cigarette smoking, hypertension, diabetes, hyperinsulinemia, abdominal obesity, family history of premature ischemic heart disease, and personal history of cerebrovascular or occlusive peripheral vascular disease.
Symptoms range from pain on exercise to paresthesias at rest in the leg and/or foot, especially at night. Large vessel pulses are usually diminished or absent. In diabetics with microangiopathy, gangrene may occur with adequate pulses. The foot is cool to cold. With significant reduction in arterial blood flow, limb elevation causes pallor (best seen on plantar foot; Bürger sign). Dependency causes delayed and exaggerated hyperemia. Auscultation over stenotic arteries reveals bruits.
There is pallor, cyanosis, livedoid vascular pattern, and loss of hair on the affected limb. Early infarctive changes include well-demarcated maplike areas of epidermal necrosis. Later, dry black gangrene may occur over the infarcted skin (purple cyanosis → white pallor → black gangrene). Shedding of slough leads to well-demarcated ulcers in which underlying structures such as tendons can be seen. Ischemic ulcers are painful; in diabetics with neuropathy and ischemic ulcers, pain may be minimal or absent.
Diagnosis is clinical, confirmed by arteriography. Differential includes pseudoxanthoma elasticum, Bürger disease (thromboangiitis obliterans), arthritis, gout, interdigital neuroma, calcanean bursitis, plantar fasciitis, rupture of plantar muscle, vasculitis, Raynaud phenomenon, disseminated intravascular coagulation, cryoglobulinemia, macroglobulinemia, septic embolization (infective endocarditis), nonseptic embolization, drug-induced necrosis (warfarin, heparin), ergot poisoning, intraarterial injection, livedo reticularis syndromes, and popliteal entrapment.
Reduce hyperlipidemia with statins, diet, and exercise, or by reducing elevated blood pressure. Patients should be helped to stop cigarette smoking and encouraged to walk regularly to create new collateral vessels and position the ischemic foot as low as possible without edema. Use heparin, warfarin, IV prostacyclins, and analgesics for symptomatic management. Endarterectomy or bypass is indicated for iliac occlusions, and any necrotic tissue should be debrided.
Atopic dermatitis, or eczema, usually begins in infancy and has peak prevalence of 15–20% in early childhood. There is often family history of atopy, allergic rhinitis, or asthma. Triggers include aeroallergens, especially dust mites and pollen; microbes; autoallergens; foods, especially eggs, milk, peanuts, soybeans, fish, and wheat; clothing, especially wool. Flares may be caused by stress and are more common in winter and after removing clothes.
Pruritus is the sine qua non—”eczema is the itch that rashes.” The constant scratching leads to a vicious cycle of itch → scratch → rash → itch → scratch.
Poorly defined erythematous patches, papules, and plaques may have scale/edema. Moist crusted erosions may result from scratching, and if oozing, represent secondary infection. Lichenification/fissures, which may be painful, occur in chronic cases. Follicular lichenification may occur especially in those with heavily pigmented skin. Rubbing may cause eyebrow alopecia, periorbital pigmentation, and infraorbital fold below eyelids (Dennie-Morgan sign).
Diagnosis is based on history and clinical exam. Differential includes seborrheic dermatitis, contact dermatitis, psoriasis, nummular eczema, dermatophytosis, and early mycosis fungoides. More rare diseases in the differential include acrodermatitis enteropathica, glucagonoma syndrome, histidinemia, phenylketonuria, and also, some immunologic disorders.
Educate patients to avoid rubbing and scratching, use emollients, and prevent secondary infection. Use wet dressings, topical glucocorticoids, and topical antibiotics when indicated and hydroxyzine for pruritus. For subacute and chronic cases prescribe baths with oil or oatmeal powder, unscented emollients, and topical anti-inflammatories such as glucocorticoids, hydroxyquinoline, or tar. Glucocorticoids are most effective but may have side effects with prolonged use. Tacrolimus and pimecrolimus work very well in minor flares and subacute atopic dermatitis. UVA-UVB phototherapy or narrow band UV (311 nm), PUVA photochemotherapy may also be effective.
Pruritus is the sine qua non—“eczema is the itch that rashes.” The constant scratching leads to a vicious cycle of itch → scratch → rash → itch → scratch.
Diagnosis is based on history and clinical exam. Differential includes seborrheic dermatitis, contact dermatitis, psoriasis, nummular eczema, dermatophytosis, and early mycosis fungoides. More rare conditions in the differential include acrodermatitis enteropathica, glucagonoma syndrome, histidinemia, phenylketonuria, and also, some immunologic disorders.