Macular Skin Lesions Flashcards
Questions to ask when seeing a macule
What is the distribution? Is there erythema, hypo or hyperpigmentation? Are there any secondary characteristics like a scale or erythema? Is pruritis present? Is the patient taking any medications? Is there a photodistribution to the eruption?
Erythematous macules
Caused by either viral exanthems or drug eruptions. Diffuse with the majority of the eruption as isolated, blanching erythematous macules on the trunk and proximal extremities.
Photodistributed macular eruptions
Occurs in a variety of skin conditions including lupus, drug reactions, dermatomyositis and polymorphous light eruptions. Often on the face, the V of the neck and dorsa of the hands and forearms.
Dermatomyositis
Upper eyelids develop a macular purplish hue and edema. Can also have erythema on the arms, shoulders, v of the neck and upper chest that is pruritic. Areas of previous erythema may resolve with persistent poikiloderma (telangiectasia on the hands and nail fold, mottled, atrophy) Systemic symptoms of fatigue, arthralgias. Grottons sign. Photodistributed macular eruptions
Nails in dermatomyositis
Mottled erythema and dilated superficial blood vessels, telangiectasia, are seen on the hands,
particularly at the proximal nail fold
Gottrons Sign
An erythematous, scaly eruption over the extensor surfaces of the metacarpophalangeal joints and digits in a patient with dermatomyositis. These lesions, called Gottron’s sign, can mimic psoriasis
Systemic Lupus erythematosus
erythema in a malar distribution, butterfly rash of the central face, diffuse erythema of sun exposed locations. Oral ulcers present as well.Photodistributed macular eruptions. Spared naso-orbital folds.
Phototoxic eruptions
Most common drug induced photoeruption. Exaggerated sunburn, often with blisters. NSAIDs, quinolones, tetracyclines, amiodarone and phenothiazines are frequent causes of phototoxicity. Occurs with higher dosages of medication, contrast to photoallergic which is any dose. Photodistributed macular eruptions
Photoallergy
lymphocyte mediated reaction caused by ultaviolet exposure. Widespread eczema in the photodistribution: face, upper chest, back of hands. Most are caused by topical agents like biocides added to soaps and fragrances like musk. Photodistributed macular eruptions
Porphyria cutanea tarda
diffuse erythema in a photodistributed pattern. Also vessicles or bullae, scarring and hypertrichosis. Macular erythema, erosions, crusts, and scars are present on the hands of this patient with porphyria cutanea tarda. Photodistributed macular eruptions
Polymorphous light eruption
Dx of exclusion. Light induced, pruritic eruption, occuring with the first intense sun exposure of the year. Diffuse erythema. Accentuation of the eruption on the arms and thighs, face may be sparred. This 12-year-old girl developed a pruritic eruption that consisted of discrete and coalescing erythematous papules on the face. The lesions were photodistributed and appeared within hours after intense sun exposure in the spring. Photodistributed macular eruptions
Hypopigmented macules
Distinguish from depigmented macules by retention of some pigment
Vitiligo
Acquired, isolated, or diffuse depigmentation. Hypopigmented areas may also occur during resolving vitiligo. Autoimmune process against melanocytes. Unknown cause.
Tinea versicolor
Hypopigmentation on the trunk and proximal extremities in a mottled distribution. Lesions can also be light brown or salmon colored. May seem to be photoaccentiated as the areas involved fail to tan and become more prominent with sun exposure. Seen in young adults and those living in humid climates. Positive KOH prep for yeast and hyphae.
Halo nevus
depigmented macule that presents in conjunction with pre existing pigmented lesion. Caused by T Cell mediated immune reaction with melanocyte nevus cells, causing the loss of all pigmentation of and around the nevus. Benign typically but can be a/s melanoma.
Pityriasis alba
Children 3-16. Patches of hypopigmentation face neck trunk and extremities. 0.5-5cm well defined irregular borders and a fine scale. Asymptomatic or pruritic. Present after sun exposure when it is accentuated by tanning. Post inflammatory hypopigmentation . A/w sun exposure and bathing. Protect affected sites from sun exposure and use moisturizer to prevent recurrence as dryness and scale may accentuate it
Post inflammatory hyperpigmentation
Postinflammatory hyperpigmentation is particularly common in darker skin types when inflammatory conditions such as acne, psoriasis, or eczema are resolving. Can occur anywhere after first eruption has resolved.
Melasma
Melasma occurs as splotchy hyperpigmented macules, typically in a photodistributed pattern, often with accentuation on the upper lip. Commonly in pregnancy with exogenous hormones.
Solar purpura
a common form of noninflammatory purpura. It presents as ecchymotic lesions predominantly on the sun-damaged skin of the forearms and dorsa of the hands of older adult individuals. From a rupture of superficial blood vessels with extravasation of blood in the dermis. Resolves spontaneously with out the sequelae of a normal bruise. Residual hyperpigmentation.
Erythema ab igne
reticular erythematous pigmented dermatosis resulting from repeated exposures to moderate heat or infrared radiation. Once common among people who sat near open fires or stoves, it is infrequently seen after the introduction of central heating. However, it is still seen in relation to occupational exposure to heat sources. Asymptomatic, may cause hyperpigmentation. Laptop on legs, bakers, heated car seats.
Solar lentigo
most commonly known as liver spots or “old age’’ spots, is a proliferation of normal melanocytes secondary to chronic solar damage. These lesions occur most commonly in whites with fair complexion who have a history of chronic sun exposure. Hyperpigmentation may vary from light to dark brown, but is uniform within an individual lesion. The diagnosis is based upon the clinical appearance of flat, oval, evenly pigmented macules in areas with chronic sun exposure
Schambergs Disease
pigmented purpuric dermatosis characterized by brownish discoloration of the skin, particularly of the lower extremities and ankle area It is caused by capillary leakage of blood and subsequent breakdown, resulting in hemosiderin staining.
Ochronosis
is a term used to describe pigment deposition that occurs in the connective tissues of patients with alkaptonuria, an autosomal recessive disorder that results from a deficiency of homogentisic acid oxidase. Brown or blue-gray discoloration of the skin may be seen on the axillary and inguinal areas, face, palms, or soles. In addition, blue-black discoloration can be apparent on skin overlying cartilage in which the pigment is deposited, such as the ears. The sclerae are also typically involved.
Fixed Drug eruption
erythematous and edematous plaques with a grayish center or frank bullae, and chronically by a dark postinflammatory pigmentation. postinflammatory hyperpigmentation and the recurrence of lesions at exactly the same site with drug reexposure. The drugs commonly involved include phenolphthalein (laxatives), tetracyclines, barbiturates, sulfonamides, n onsteroidalantiinflammatory drugs (NSAIDs), and salicylates
Melanoma
A changing, pigmented macule, Asymmetry, Border irregular, change in color, diameter > 6mm,
