ARTICLE
Topical immunotherapy by induction and repeated elicitation of an allergic
contact dermatitis is at present the most effective mode of treatment
for alopecia areata (AA). However, the method is not successful in all
cases. Therefore, it would be desirable to know the prognostic factors
that influence the therapeutic outcome as a basis for an improved patient
selection. From the clinical point of view several such prognostic criteria
have been identified: 1. Type of AA and extent of hair loss: patients
with subtotal or total scalp hair loss, alopecia universalis, ophiasis
type and diffuse alopecia areata have a less favorable prognosis than
patients with patchy AA [1-10]. 2. Duration of the disease before treatment:
an adverse prognostic effect in patients with longstanding disease has
been described by numerous authors [4-15]. 3. Presence of nail changes
has been reported to be a further factor of negative prognostic significance
[8, 10, 15]. 4. Concomitant atopic dermatitis turned out in some studies
to be also associated with a poor prognosis [10, 12, 13, 15].
In contrast to these extensive investigations of clinical parameters,
histopathological features that may exert an influence on the therapeutic
outcome of topical immunotherapy in AA have been explored in only two
studies so far [16, 17]. Biopsies had been taken after treatment in both
studies. Furthermore these studies gave conflicting results. Therefore,
we re-examined the histopathological changes seen in scalp biopsies that
had been taken before treatment, in order to compare features of untreated
AA in responders and non-responders to topical immunotherapy.
Material and methods
Patients
Scalp biopsies were taken from the edge of expanding lesions with informed
consent from 85 patients with AA before initiation of therapy. For clinical
data see Tables I
and II. After skin biopsy, sensitization was induced by painting
25 cm2 of the patient's scalp with 2% DCP dissolved in acetone.
A contact dermatitis was elicited and maintained by weekly unilateral
application of DCP concentrations varying from 0.0000001% to 1%. Unilateral
treatment was carried out to exclude the possibility that spontaneous
remission might be mistaken for therapeutic response. When unilateral
hair regrowth was noted, DCP was applied to the entire scalp. All patients
were treated for at least 6 months. Patients who showed cosmetically good
results after this period of treatment were classified as responders,
those who did not show any or only unsatisfying hair regrowth or those
who developed hair loss after initial regrowth were categorized as non-responders.
According to this dichotomous classification, the study group comprised
40 responders and 45 non-responders.
Methods
Biopsy specimens were fixed in phosphate-buffered 10% neutral formalin
and routinely processed in paraffin wax for light microscopy. Vertical
sections were stained with hematoxylin-eosin. In addition, sections from
50 patients (27 reponders and 23 non-responders) were stained by the elastica-van
Gieson technique.
Two independent investigators evaluated the following parameters:
In all 85 sections the degree of perifollicular lymphocytic infiltration
was assessed by the use of three categories: mild (+), moderate (++),
pronounced (+++) infiltrate. Representative examples of these categories
are shown in Figures 1
to 3.
In addition, the following parameters were assessed in the same way
in those 50 samples that had been stained by the elastica-van-Gieson technique:
Perifollicular proliferation of fibrous tissue: mild (+), moderate (++),
pronounced (+++); size and structure of hair follicles: miniaturized,
medium-sized, normal-sized.
Statistical analysis
The chi-square test was employed to determine statistical significance.
Results
Perifollicular lymphocytic infiltration
A predominantly peribulbar and perivascular lymphocytic infiltrate with
single lymphocytes invading the hair bulb itself was found in all sections.
In some sections only mild inflammatory changes were seen, whereas others
showed a rather dense lymphocytic infiltration. As shown in Table
III and Figure 4,
most of the non-responders had a moderate to pronounced perifollicular
lymphocytic infiltration, whereas the majority of responders had only
mild or moderately dense infiltrates. Nevertheless, 6 responders showed
a pronounced, and 9 non-responders only a mild infiltration. The difference
between both groups was statistically significant (p < or = 0.01).
Perifollicular proliferation of fibrous tissue and
formation of fibrous tracts below miniaturized hair follicles
These histopathological features were found in both responders and non-responders
with no difference in the distribution to the 3 assessed degrees (Table
IV). The observed changes in the connective tissue components
resembled those occurring in normal catagen. In neither group was there
any evidence of scarring.
Size and structure of hair follicles
In both responders and non-responders almost all sections revealed miniaturized
hair follicles (Table V),
characterized by a reduced size and a bulb located in the mid or
lower dermis, or at least medium-sized hair follicles with a bulb located
at the dermis subcutis transition or in the upper subcutis. The
miniaturized hair follicles were followed by a fibrous tract extending
into the subcutis, and showed the structure of hair follicles in anagen
or in catagen. Only mild degenerative changes such as vacuolization of
epithelial cells around the dermal papilla could be observed in some hair
bulbs. No complete follicular destruction was seen in any biopsy. Evaluation
of size and structure of hair follicles revealed no difference between
responders and non-responders.
Discussion
A more or less dense perifollicular lymphocytic infiltrate surrounding
the lower parts and bulbs of anagen hair follicles with single lymphocytes
invading the hair bulb itself, is one of the main histopathological signs
of AA. According to the investigations of Headington [18] and Goos [19],
the density of the lymphocytic infiltrate is poorly correlated with the
severity or the duration of the disease. In contrast to the incoherence
between the degree of infiltration and the spontaneous course of the disease,
our results show that there is a correlation between infiltration and
response to topical immunotherapy. Non-responders to topical sensitizers
tend to have rather pronounced inflammatory changes with dense perifollicular
and perivascular lymphocytic infiltrates, whereas responders usually show
only mild lymphocytic infiltrations. However, 6 patients with a pronounced
lymphocytic infiltration showed hair regrowth after topical immunotherapy
and, on the other hand, 9 patients with only a mild infiltration did not
respond to therapy. Hence, our results suggest that a marked inflammatory
reaction in AA can be taken as a negative prognostic factor regarding
topical immunotherapy. Nevertheless, it is not impossible that even those
patients experience hair regrowth with therapy with a topical senzitizer.
With regards to the degree of miniaturization of hair follicles and
perifollicular proliferation of fibrous tissue, no difference could be
observed between responders and non-responders. Miniaturized hair follicles
and thickened perifollicular fibrous tissue are common features of AA.
The miniaturization of hair follicles has been interpreted as a transformation
into catagen and subsequently telogen by Ackerman [20] who described a
thickened corrugated glassy membrane as a sign of catagen. Messenger et
al. [21] advanced the hypothesis of a premature entry of affected
anagen follicles into telogen, re-entry into anagen and subsequently truncated
hair cycles during the active period of the disease. These authors observed
that some follicles survived in anagen, producing an exclamation mark
hair because of the impairment of cortex formation. After entry into telogen
the hair follicle remains unaffected and is able to return to anagen.
In this way, miniaturization and connective tissue proliferation would
reflect an accelerated cycling of the affected hair follicle.
Apart from the thickening of the perifollicular fibrous tissue that
can be interpreted as a physiological feature of catagen transformation
[20], we observed neither scarring patterns, as reported by Fanti et
al. [16], nor severe destruction of hair follicles, as described by
Uno et al. [17]. The only degenerative change we found was vacuolization
of some bulbar keratinocytes.
In summary, our results indicate that non-responders to topical immunotherapy
of AA tend to have a rather pronounced perifollicular lymphocytic infiltrate.
Hence, in those cases where a scalp biopsy is performed prior to therapy,
the presence of a dense inflammatory infiltrate can be taken as an unfavorable
prognostic feature regarding the outcome of topical immunotherapy.
REFERENCES
1. Happle R, Echternacht K. Induction of hair growth in alopecia areata
with DNCB. Lancet 1977; ii: 1002-3.
2. Happle R, Cebulla K, Echternacht-Happle K. Dinitrochlorobenzene therapy
for alopecia areata. Arch Dermatol 1978; 114: 1629-31.
3. Happle R. DNCB-Therapie der Alopecia areata. Z Hautkr 1979;
54: 426-9.
4. Happle R, Kalveram KJ, Büchner U, Echternacht-Happle K, Göggelmann
W, Summer KH. Contact allergy as a therapeutic tool for alopecia areata:
application of squaric acid dibutylester. Dermatologica 1980; 161:
289-97.
5. Friedmann PS. Dinitrocholorobenzene and alopecia (letter). Lancet
1979; i: 1412.
6. Friedmann PS. Response of alopecia areata to DNCB: influence of auto-antibodies
and route of sensitization. Br J Dermatol 1981; 105: 285-9.
7. Case PC, Mitchell AJ, Swanson NA, Vanderveen EE, Ellis CN, Headington
JT. Topical immunotherapy of alopecia areata with squaric acid dibutylester.
J Am Acad Dermatol 1984; 10: 447-51.
8. Van der Steen PHM, van Baar HMJ, Happle R, Boezeman JBM, Perret CM.
Prognostic factors in the treatment of alopecia areata with diphenylcyclopropenone.
J Am Acad Dermatol 1991; 24: 227-30.
9. Van der Steen PHM, Boezeman JBM, Happle R. Topical immunotherapy
for alopecia areata: re-evaluation of 139 cases after an additional follow-up
period of 19 months. Dermatology 1992; 184: 198-201.
10. Weise K, Kretzschmar L, John SM, Hamm H. Topical immunotherapy in
alopecia areata: anamnestic and clinical criteria of prognostic significance.
Dermatology 1996; 192: 129-33.
11. Breuillard F. Dinitrochlorobenzene in alopecia areata (letter).
Lancet 1978; ii: 1304.
12. De Prost Y, Paquez F, Touraine R. Dinitrochlorobenzene treatment
of alopecia areata. Arch Dermatol 1982; 118: 542-5.
13. Temmermann L, De Weert J, De Keyser L, Kint A. Treatment of alopecia
areata with dinitrochlorobenzene. Acta Derm Venereol (Stockh) 1984;
64: 441-4.
14. Ochsendorf FR, Mitrou G, Milbradt R. Therapie der Alopecia areata
mit Diphenylcyclopropenon. Z Hautkr 1988; 63: 94-100.
15. Gordon PM, Aldridge RD, McVittie E, Hunter JAA. Topical diphencyprone
for alopecia areata: evaluation of 48 cases after 30 months' follow-up.
Br J Dermatol 1996; 134: 869-71.
16. Fanti PA, Tosti A, Bardazzi F, Guerra L, Morelli R, Cameli N. Alopecia
areata: a pathological study of non responder patients. Am J Dermatopathol
1994; 16: 167-70.
17. Uno H, Orecchia G. Histopathology of alopecia areata: the relation
with clinical parameters and response to a topical sensitizer. In: Van
Neste D, Lachapelle JM, Antonie JL, eds. Trends in Human Hair Research
and Alopecia Research. Kluwer Academic Publishers, Dordrecht 1989:
273-81.
18. Headington JT. The histopathology of alopecia areata. J Invest
Dermatol 1991; 96 (suppl.): 69S.
19. Goos M. Zur Histopathologie der Alopecia areata. Arch Dermatol
Forsch 1971; 240: 160-72.
20. Ackerman AB. Alopecia areata. In: Ackerman AB, Ragaz A, eds. The
Lives of Lesions: Chronology in Dermatopathology. Masson Publishing
USA, Inc, 1984: 13-9.
21. Messenger AG, Slater DN, Bleehen SS. Alopecia areata: alterations
in the hair growth cycle and correlation with the follicular pathology.
Br J Dermatol 1986; 114: 337-47.
|
Version imprimable
