(1)
Department of Dermatology, University of Pennsylvania, Penn Presbyterian Medical Center Medical Arts Building, Philadelphia, PA, USA
12.1.1 Localized Hyperpigmentation
12.2.1 Localized Hypopigmentation
12.2.3 Generalized Hypopigmentation
12.2.4 Leukodermas (Depigmentation)
Abstract
Pigmentary disorders are characterized primarily by an increase or decrease in pigment. In this chapter, the type of pigment change is used to characterize these disorders.
Keywords
HyperpigmentationHypopigmentationVitiligo12.1 Hyperpigmented Conditions
12.1.1 Localized Hyperpigmentation
(a)
Melanocytic neoplasms
See also Neoplastic: Melanocytic neoplasms
(b)
Dermal melanocytosis
See also Neoplastic: Melanocytic neoplasms
(c)
Lentigines
See also Neoplastic: Melanocytic neoplasms
(d)
Café-au-lait macules
See also Neoplastic: Melanocytic neoplasms
(e)
Longitudinal melanonychia
Ddx includes racial predisposition, trauma, drugs, pregnancy, Addison disease, Peutz-Jeghers syndrome, Laugier-Hunziker syndrome, SCC, onychomycosis, benign nail matrix nevi, and melanoma
Of more concern if involves a single nail, or demonstrates signs concerning for melanoma (e.g., Hutchinson’s sign with pigment extending onto the proximal nail fold)
12.1.2 Generalized Hyperpigmentation
(a)
Post-inflammatory hyperpigmentation (PIH)
Aka post-inflammatory pigment alteration (PIPA)
Melanin deposits in dermal melanophages secondary to inflammation
(b)
Erythema dyschromicum perstans (EDP)
“Ashy dermatosis” of blue-grey macules; may be post- inflammatory, some consider this a variant of lichen planus
Path: vacuolar change, perivascular or interface lymphs, and melanin incontinence
Increased incidence in Latin Americans
See also Papulosquamous: Lichenoid
(c)
Lichenoid dermatoses
These tend to leave more post-inflammatory pigment given the infiltrate along the dermal-epidermal junction
See also Papulosquamous: Lichenoid
I.
Lichen planus pigmentosus
A postinflammatory hyperpigmented form of LP that may be similar to EDP
(d)
Pigment deposition
See also Dermal: Depositional: Pigment deposition
I.
Ochronosis
Inherited/endogeneous form (alkaptonuria) and exogenous form (typically from hydroquinone)
II.
Hemochromatosis (iron deposition)
See also Nutritional Diseases
III.
Argyria (silver deposition)
IV.
Tattoo (pigment deposition)
V.
Drug-induced pigmentary deposition
A.
Minocycline
Blue pigment indicates iron on path
Type 1: blue-black at sites of acne, inflammation; Path = iron in dermis
Type 2: blue-grey on normal skin; anterior legs; Path = melanin and iron in dermis/subcutis
Type 3: diffuse muddy brown on sun-exposed areas; Path = increased basal layer melanin, dermal melanophages, no iron
B.
Amiodarone
Slate-gray photodistributed pigmentation
C.
Other medications
Clofazimine (lipofuscin), diltiazem, imipramine
(e)
Incontinentia pigmenti
See also Vesiculobullous: Intraepidermal blisters
Four stages: 1. Vesicular, 2. Verrucous, 3. Hyperpigmentation, 4. Hypopigmentation
(f)
Addison’s disease (adrenal insufficiency)
Hyperpigmenation, especially of sun-exposed areas, areas of trauma/scars, and creases/areolae/axillae/genitalia
Cultural note: famous case of President John F. Kennedy, who had hyperpigmented skin likely related to his Addison’s disease
(g)
Necrolytic acral erythema
Hyperpigmented plaques on dorsal feet/heels, from Hepatitis C
12.2 Hypopigmented Conditions
12.2.1 Localized Hypopigmentation
(a)
Pityriasis alba
See also Eczematous: Atopic dermatitisRelated posts:
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