PATHOLOGY OF ALOPECIA AREATA. [Extracted from the American Journal of the Medical Sciences for July, 1870.] 
PATHOLOGY OF ALOPECIA AEEATA. 
By L. A. DUHRING, M.D., 
OP PHILADELPHIA. 
For the last twenty years micrographers and dermatologists have been 
discussing whether alopecia areata is due to the presence of a fungus or 
to other causes. This question is worthy of investigation in order that we 
may be able to treat the disease in a rational manner. 
Alopecia areata is a disease confined to the hair system, generally 
met with upon the scalp, and characterized by whitish bald patches occur- 
ring in one or more parts, various in shape and size, but generally circular. 
This affection must not be confounded with tinea tonsurans, which it 
often closely resembles, for the latter exists under totally different condi- 
tions from those present in alopecia areata, and a distinction must be drawn 
between them. Passing over the early literature of this affection, Gruby, 
in 1848, declared that he had discovered a fungus in this disease, to which 
he gave the name of microsporon audouini. Shortly after this many 
researches and experiments were made in quest of this fungus, some 
corroborative of the statement of Gruby, others contradictory of it. The 
discussion has continued to the present, day, and the only means of solving 
the problem is by aid of the microscope. The fact that this affection 
bears a resemblance in its seat and appearance to tinea tonsurans should 
not influence us in our investigation. The question to be solved is : When 
we examine the hairs and epidermis properly do we see a fungus or not? 
This appears like an easy problem to solve; at the same time it is but 
just to remark that the investigation requires a certain amount of skill 
and practice to avoid error. 
The upholders of the present day of the parasitic nature of alopecia 
areata, foremost amongst whom are Tilbury Fox, Bazin, and Hardy, con- 
tend that the disease is produced by the presence of the microsporon au- 
douini, and that this is the only cause of the disorder. This fungus is 
represented as consisting of mycelium and spores, the former being more 
abundant than in the trichophyton, while the latter are smaller and less 
numerous, and have all the general properties of the other fungi, and are 
found and demonstrated in the same manner as the trichophyton and achorion Schoenleinii. Though the object of the present remarks is to 
refer particularly to the nature and cause of the disease under considera- 
tion, yet, perhaps, a few preliminary words in regard to the mode of exa- 
mination of the hairs will not be out of place. Among the many reagents 
we shall only refer to three: solution of potassa, glycerine, and water, and 
it is proper all three should be employed for a thorough examination, 
though when in search of a suspected fungus it is preferable to use the 
first-named solution of the following strength : Potassa fusa twenty-five 
grains, aqua destillata one ounce. Potassa has a definite action upon the 
epidermic tissue, breaking up and dissolving the adhesions of the cells at 
once, while after contact for some time it completely destroys the cell struc- 
ture, the destructive action varying according to the strength of the solu- 
tion used. Applied for immediate use of the above strength it merely 
separates and frees the cells from one another, without acting injuriously 
upon the epidermic cells of the hair itself to such an extent as to render 
its employment objectionable. At the same time a solution of potassa has 
no determined destructive action upon vegetable parasites; on the contrary, 
its use is always indicated in the search for these delicate structures, since 
their characters are more plainly brought out by its breaking up the bed 
of epidermic tissue, thus leading to their detection, when otherwise this 
would be extremely difficult, if not impossible. In order to get rid of 
superfluous fatty matter a few drops of sulphuric ether should be used, 
though this will by no means clear the hair and field completely from fat 
and sebum. For the purpose of obtaining a proper view of the hair, about 
five hundred diameters magnifying power is required, and it is well even 
to use higher powers occasionally to determine doubtful points; moreover a 
strong light is necessary to penetrate the substance of the hair. 
Alopecia areata presents different appearances in its various stages, but 
if a patch be examined when the disease first shows itself, the hairs are seen 
to be fewer in number than normal, and diminished in bulk, intermingled 
with little, short, broken-off hairs scattered here and there over the patch. 
In the course of a week or two all these will have disappeared, and a per- 
fectly bald spot with a clearly-defined margin of apparently sound hairs 
will be seen remaining. It is in these short, stumpy, broken-off hairs that 
we might expect to find evidence of disease, or at least the most marked 
alteration. These broken-off hairs, when extracted with the forceps, come 
out of their sheath without any resistance, and when placed on a glass 
slip with a drop of solution of potassa covered with a thin glass, and 
placed under the microscope, are seen terminating abruptly in a pear or 
club-shaped extremity, instead of the thick, long, spongy, luxuriant-looking 
bulb with its well-defined, transverse striae, seen in normal hairs plucked 
from the scalp. The bulb is contracted, shrivelled, and atrophied, and sur- 
rounded with only a scanty supply of sebum and epidermic cells. Its peri- 
phery is generally sharply defined with a zigzag border, or in other cases presents a rounded appearance. The root retains its normal look with the 
exception of being diminished in size. In the shaft, however, we notice, as 
we approach the free end, an even and gradual distension, terminating 
generally in an oval swelling or bulging close to the end of the hair, and 
then suddenly tapering down, finishing in a broken, ragged extremity. 
These are the appearances we invariably find in a marked case of alopecia 
areata, with no sign of fungus / 
When the hairs on the patch that have not been broken, or such as are 
diseased and are just ready to break, are examined, we see the same atro- 
phied, shrunken bulb, the same feeble root, and the shaft increasing in 
diameter towards the free end. Many of them escape being injured and 
broken, and, having been detached from their papilla, act as a foreign sub- 
stance, and are rapidly cast off. 
Is the shrunken, atrophied condition of the bulb characteristic of this 
disease, or is it found elsewhere ? If a hair that has fallen naturally fronl 
a healthy head be examined, almost exactly the same appearance of the 
bulb is seen ; it is shrivelled and dead. This atrophied bulb is also found 
in hairs that have lived their normal life, and, having been detached from 
their papilla, are thrown off; in one case it is health and in the other dis- 
ease. Instead of the normal growth and death of the hair, we have a 
sudden arrest of nutrition from some cause, and a rapid wasting and death 
in consequence, due most probably to atrophy of the papilla itself. If 
there be a defective nutrition in the papilla, a paralyzation of nerve force, 
the bulb will suffer first, but the life of the whole hair is quickly affected, 
it withers, dies, and is cast away with its blighted bulb and shaft. 
Owing to some cause or other yet unknown this temporary loss of 
vitality in a part occurs, and there is alopecia areata, in some cases to a 
slight extent, in others involving the whole hair system, scalp, axillae, 
and pubes ; thus the entire body is deprived temporarily of its hair. 
Such in a few words seems to be the most rational and probable ex- 
planation of the loss of hair in the disease under discussion, namely, a 
sudden arrest of nutrition in the papilla. The bulging or oval distension 
of the shaft at its end, referred to, due, as some consider, to the presence of 
fungus, is easily explained as follows : The shaft not receiving its proper 
nourishment from the papilla, its extreme end suffers most, and does not 
thrive; the filaments not being sustained as usual and losing their vitality, 
tend to separate and disintegrate, thus stretching the epidermic mem- 
brane and causing the appearance described. The fact that the filaments 
do separate is clearly demonstrated with a high power and a strong, pene- 
trable light; moreover this distension to a greater or less extent is con- 
stant, and in the same position in every case. 
When the devitalized and brittle hairs are subjected to violence, as 
from a comb or brush, they are broken off at the point where there is the 
greatest force exerted, just where they emerge from the scalp, leaving the jagged end, a small portion of the shaft, the root and bulb. In other 
words, nothing but the stumpy, broken hairs remain in the scalp; these 
soon loosen from their papilla, separate from the sheath, and are cast off a 
dead substance. If the hair breaks because it is greatly distended and 
brittle, it might be expected to break at the bulging, the point of its 
greatest distension, and instead of a tapering end, a wide-spread, bushy 
extremity be found. The hair undoubtedly does break at the point of 
greatest distension, but as soon as this happens the epidermic membrane, 
which gives contour to the hair, contracts and holds together the free 
filaments; thus acting as an elastic membrane and not allowing the broken 
filaments to spread themselves. 
It may be asked: How does it happen that a fungus should have been so 
minutely described, if none actually exists ? About the roots and shafts of 
all hairs normal or diseased, varying with the case, there exists an appre- 
ciable amount of sebum, broken-up epidermic cells, and debris. When sub- 
jected to a reagent, sebum has a tendency to split and break up into fine 
particles, and these often adhere so closely and with such tenacity to the 
hairs as to accurately resemble spores. 
I cannot help thinking that it is to these deceptive little particles of 
sebum that the name of microsporon audouini owes its existence ! 
Upon two occasions the supposed fungus, the microsporon audouini, 
was demonstrated to me by experienced and well-known dermatologists ; 
in both cases I had the satisfaction of proving conclusively by means of 
reagents, that the regularly divided, rounded, bright little bodies were 
simply aggregations of sebum. 
I may add, moreover, that I have found this curious and spore-like 
arrangement of sebum upon hairs, normal in every respect. In conclu- 
sion, let it be borne in mind that the foregoing observations apply exclu- 
sively to the short, broken-off hairs which are found in the earliest recog- 
nizable stage, the typical hairs of alopecia areata; after this period the 
disease presents a different appearance, namely, complete baldness, with an 
edge of apparently normal hairs, which continues until recovery begins.