Part 57

A nævus to which is added hypertrophy of the papillæ, giving rise to a furrowed and uneven surface.

#What is linear nævus?#

Linear nævus is a formation usually of a verrucous character, more or less pigmented, sometimes slightly scaly, occurring in band-like or zoster-like areas, and, as a rule, unilaterally.

#What is nævus lipomatodes?#

A nævus with excessive fat and connective-tissue hypertrophy.

#State the etiology of nævus pigmentosus.#

The causes are obscure. The growths are usually congenital; but the smooth, non-hairy moles may be acquired.

#Give the pathology of nævus pigmentosus.#

Microscopical examination shows a marked increase in the pigment in the lowest layers of the rete mucosum, as well as more or less pigmentation in the corium usually following the course of the bloodvessels; in the verrucous variety the papillæ are greatly hypertrophied, in addition to the increased pigmentation. There is, as a rule, more or less connective-tissue hypertrophy.

#What is the treatment of nævus pigmentosus?#

In many instances interference is scarcely called for, but when demanded consists in the removal of the formation either by the knife, by caustics, or by electrolysis. This last is, in the milder varieties at least, perhaps the best method, as it is less likely to be followed by disfiguring cicatrices. In nævus pilosus the removal of the hairs alone by electrolysis is not infrequently followed by a decided diminution of the pigmentation. In recent years both liquid air and carbon dioxide have also been used successfully in the removal of these growths. Pigmented nævi, which show the least tendency to growth or degenerative change, should be radically removed, as they not infrequently lead to carcinomatous and sarcomatous growths.

#Ichthyosis.# (Synonym: Fish-skin Disease.)

#Give a descriptive definition of ichthyosis.#

Ichthyosis is a chronic, hypertrophic disease, characterized by dryness and scaliness of the skin, with a variable amount of papillary growth.

#At what age is ichthyosis first observed?#

It is first noticed in infancy or early childhood. In rare instances it is congenital (ichthyosis congenita), and in such cases it is usually severe, and of a grave type; the children are, as a rule, prematurely born, and frequently do not survive many days or weeks.

#What extent of surface is involved?#

Usually the whole surface, but it is most marked upon the extensor surfaces of the arms and legs, especially at the elbows and knees; the face and scalp, in mild cases, often remain free.

#Name the two varieties of ichthyosis usually described.#

Ichthyosis simplex and ichthyosis hystrix, terms commonly employed to designate the mild and severe forms respectively.

#Describe the clinical appearances of ichthyosis.#

The milder forms of the disease may be so slight as to give rise to simple dryness or harshness of the skin (xeroderma); but as commonly met with it is more developed, more or less marked scaliness in the form of thin or somewhat thick epidermal plates being present. The papillæ of the skin are often slightly hypertrophied. In slight cases the color of the scales is usually light and pearly; in the more marked examples it is dark gray, olive green or black.

In the severe variety--ichthyosis hystrix--in addition to scaliness there is marked papillary hypertrophy, forming warty or spinous patches. This type is rare, and, as a rule, the surface involved is more or less limited.

#Are there any inflammatory symptoms in ichthyosis?#

No. In fact, beyond the disfigurement, the disease causes no inconvenience; in those well-marked cases, however, in which the scales are thick and more or less immovable, the natural mobility of the parts is compromised and fissuring often occurs. In the winter months, in the severer cases, exposed parts may become slightly eczematous.

#Does ichthyosis vary somewhat with the season?#

Yes. In all cases the disease is better in the warm months, and in the mild forms may entirely disappear during this time. This favorable change is purely mechanical--due to the maceration to which the increased activity of the sweat glands gives rise.

#Is the general health affected in ichthyosis?#