Milia and Seborrheic Keratosis

Milia, also known as milk spots or oil seeds, are benign, keratin-filled cysts that can appear just under the epidermis or on the roof of the mouth. They are commonly associated with newborn babies but can appear on people of all ages. They are usually found around the nose and eyes, and sometimes on the genitalia, often mistaken by those infected as warts or other STDs.

In children milia often disappears within two to four weeks. In adults it may require removal by a physician or an esthetician. Milia can sometimes be a result of harsh face washes or from repeated heat stress from hot showering on people with sensitive skins. Milia can be confused with stubborn whiteheads.

A seborrheic keratosis (also known as “Seborrheic verruca,” “Senile keratosis,” and “Senile wart”) is a noncancerous benign skin growth that originates in keratinocytes. Like liver spots, seborrheic keratoses are seen more often as people age. In fact they are sometimes humorously referred to as the “barnacles of old age”.

They appear in various colors, from light tan to black. They are round or oval, feel flat or slightly elevated (like the scab from a healing wound), and range in size from very small to more than 2.5 centimetres (1.0 in) across. They can resemble warts, though they have no viral origins. They can also resemble melanoma skin cancer, though they are unrelated to melanoma as well. Because only the top layers of the epidermis are involved, seborrheic keratoses are often described as having a “pasted on” appearance. Some dermatologists refer to seborrheic keratoses as “seborrheic warts”, however these lesions are usually not associated with HPV, and therefore such nomenclature should be discouraged.

Classification

Seborrheic keratoses may be divided into the following types:

* Common seborrheic keratosis (Basal cell papilloma, Solid seborrheic keratosis)
* Reticulated seborrheic keratosis (Adenoid seborrheic keratosis)

Reticulated seborrheic keratosis (also known as “Adenoid seborrheic keratosis”) is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface, and with keratin cysts seen histologically.

* Stucco keratosis (Digitate seborrheic keratosis, Hyperkeratotic seborrheic keratosis, Serrated seborrheic keratosis, Verrucous seborrheic

keratosis) Stucco keratosis (also known as “Digitate seborrheic keratosis,” “Hyperkeratotic seborrheic keratosis,” “Serrated seborrheic keratosis,” and “Verrucous seborrheic keratosis”) is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface, and with church-spire-like projections of epidermal cells around collagen seen histologically.

* Clonal seborrheic keratosis
Clonal seborrheic keratosis is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface, and with round, loosely packed nests of cells seen histologically.

* Irritated seborrheic keratosis (Basosquamous cell acanthoma, Inflamed seborrheic keratosis)

* Seborrheic keratosis with squamous atypia

Seborrheic keratosis with squamous atypia is a less common cutaneous condition characterized by a skin lesion with a dull or lackluster surface, and with round, loosely packed nests of cells seen histologically.

* Melanoacanthoma (Pigmented seborrheic keratosis)

Melanoacanthoma (also known as “Pigmented seborrheic keratosis”) is a common, benign, darkly pigmented cutaneous condition characterized by a skin lesion with a dull or lackluster surface.

* Dermatosis papulosa nigra

Dermatosis papulosa nigra (DPN) is a condition of many small, benign skin lesions on that face that closely simulate seborrheic keratoses, a condition generally presenting on dark-skinned individuals.

They should not be confused for Leser-Trélat sign, a sudden explosion of lesions due to a growing tumor.

* The sign of Leser-Trélat

The Leser-Trélat sign is the explosive onset of multiple seborrheic keratoses (many pigmented skin lesions), often with an inflammatory base. This can be an ominous sign of internal malignancy as part of a paraneoplastic syndrome. In addition to the development of new lesions, preexisting ones frequently increase in size and become symptomatic. It is named for Edmund Leser and Ulysse Trélat.

Although most associated neoplasms are gastrointestinal adenocarcinomas (stomach, liver, colorectal and pancreas), breast, lung, and urinary tract cancers, as well as lymphoid malignancies are associated with this impressive rash. It is likely that various cytokines and other growth factors produced by the neoplasm are responsible for the abrupt appearance of the seborrheic keratoses. In some cases, paraneoplastic acanthosis nigricans accompanies the sign of Leser-Trélat.

Variances of Seborrheic Keratosis:

Dermatosis Papulosis Nigra: Often are small papules. Pinpoint to a few millimeters in size. More commonly found in dark-skinned persons.

Stucco Keratosis: Often are light brown to off-white. Pinpoint to a few millimeters in size. Often found on the distal tibia, ankle, and foot.

Diagnosis: Visual diagnosis is made by the “stuck on” appearance, horny pearls or cysts embedded in the structure. Darkly pigmented lesions can be hard to distinguish from nodular melanomas. If in doubt, a skin biopsy should be performed. Thin seborrheic keratoses on facial skin can be very difficult to differentiate from lentigo maligna even with dermatoscopy.

Clinically, epidermal nevi are similar to seborrheic keratoses in appearance. Epidermal nevi are usually present at or near birth. Condylomas and warts can clinically resemble seborrheic keratoses, and dermatoscopy can be helpful. On the penis and genital skin, differentiation between condylomas and seborrheic keratoses can be difficult and may require a skin biopsy.

Treatment
When correctly diagnosed, no treatment is necessary. There is a small risk of localized infection caused by picking at the lesion. If a growth becomes excessively itchy or is irritated by clothing or jewelry, it can be removed by cryosurgery.

Small lesions can be treated with light electrocautery. Larger lesions can be treated with electrodessication and curettage, shave excision, or cryotherapy. When correctly performed, removal of seborrheic keratoses will not cause much visible scarring except in darkly colored persons.

Cause
The cause of seborrheic keratosis is unclear. Because they are common on sun-exposed areas such as the back, arms, face, and neck, ultraviolet light

may play a role, as may genetics.[8] A mutation of a gene coding for a growth factor receptor, (FGFR3), has been associated with seborrheic keratosis.

Etymology
The term “seborrheic keratosis” combines the adjective form of seborrhea, keratinocyte (referring to the part of the epidermis that produces keratin), and the suffix -osis, meaning abnormal.