Disorders of Hyperpigmentation Flashcards
What groups are more likely to get melasma?
Young to middle-aged women of Asian, Hispanic, African or Middle Eastern descent (Fitz III and above often)
Though the exact pathophysiology of melasma is largely unknown, what is an important/primary trigger?
UV radiation and visible light may activate hyper-functional melanocytes to produce more melanin
What factors may worsen melasma?
Sun exposure, estrogen (pregnancy, OCP’s and HRT), genetic influences, thyroid dysfunction, and medications like phenytoin and other phototoxic medications
What is the clinical presentation of melasma and what are the 3 clinical patterns?
Symmetric light to dark brown/gray irregular patches on the face
3 types: 1. Centrofacial, 2. Malar, 3. Mandibular
What are the 4 types of melasma (not clinical subtypes)?
Epidermal, dermal, mixed, and indeterminate
How can the Wood’s lamp help differentiation epidermal from other types of melasma?
The epidermal type is accentuated by the Wood’s lamp whereas the dermal type is not accentuated (or ones that are primarily dermal)
Treatments for melasma?
Everybody should be encouraged to use broad-spectrum sun protection/avoidance. Hydroquinone, tretinoin, steroids, and resurfacing can be offered as well. Some are starting to use systemic tx like tranexamic acid. Patients must be asked about hx of clotting disorders/DVT/stroke etc as this can increase the propensity to clot.
What is the histology of lichen planus pigmentosus?
Sparse band of lymphs with mild perivascular infiltrate in upper dermis. Also see dermal melanophages and basal cell degeneration (note this is one of the few lichenoid disorders with vacuolar interface inflammation
What skin types are most commonly affected by lichen planus pigmentosus?
Skin types III-V
What is the clinical appearance of lichen planus pigmentosus?
Irregular oval, brown to gray-brown macules and patches in sun exposed or intertriginous areas
Usually symmetric, may be reticulated or follicluar in pattern too
What is linear and whorled nevoid hypermelanosis?
Heterogenous, sporadic mosaic skin condition in which a clone of skin cells leads to increased pigment production
What is the clinical appearance of whorled nevoid hypermelanosis?
Hyperpigmented macular Blaschkoid whorls and streaks typically occuring before 1 year of age
What are some associated findings with whorled nevoid hypermelanosis?
Neurologic, MSK, or cardiac findings can be seen
Tx of whorled nevoid hypermelanosis?
No tx, persists indefinitely
Who is affected by prurigo pigmentosa?
Occurs in young adults F>M; Japanese especially
