British Journal of Dermatology {if)-l9) l o i , 237.

Correspondence Immunofluorescence study of pityriasis lichenoides SIR, We wish to comment on the paper by Drs R.Clayton and G.Haffenden 'An immunofluorescence study of pityriasis lichenoides' {British Journal of Dermatology, (1978) 99, 491). The authors reported IgM and C3 deposits in superficial dermal vessels and along the dermal-epidermal junction (DEJ) in thirty-one of forty-three lesions of twenty-seven patients with pityriasis lichenoides (PL). We report results of direct immunofluorescence study of twenty-one fresh lesions of PL (histologically proven PL). We never saw any IgG, IgM or IgA deposits in any of these biopsies. Complement deposits were observed in only four cases, with a granular pattern: in one case along the DEJ, in three cases in dermal vessels walls. Among these three cases was a patient suffering from both PL and systemic lupus erythematosus (SLE). On the other hand, we observed C3 and IgM skin deposits in other diseases, such as SLE. Thus, in our own experience, the pattern described by Drs R.Clayton and G.Haffenden does not appear to be characteristic of PL. FRA INSERM No. 11 Recherche Dermatologique et Immunologie Clinique Dermatologique,

J. THIVOLET M. FAtniE

Pavilion R,

B. CHOUVET

Hopital Edouard Herriot, 69374 Lyon Cedex 2, France

SIR, We are very interested to hear of another immunofluorescence (IF) study of fresh lesions of pityriasis lichenoides (PL). The different results are striking. It is, therefore, hoped that other centres will publish their findings for consideration. We take this opportunity to publish more photographs of the I F we have seen (Figs i and 2). These should be considered with those in our original publication, TL—an immune complex disease' (Clayton et al, 1977)We wish to stress that the IF in PL is usually not so extensive, either at the dermal-epidermal junction or in the vessels, as is seen in other conditions. It is granular at both sites. Often only one or two vessels are involved, whereas in other immune complex vasculitides the majority of vessels are involved. At the dermal epidermal junction the I F is unlike that found in lupus erythematosus, being finer and more intermittent. We recognize that the dermal-epidermal junction I F alone is not especially significant as it is similar to that seen in 26",, of normal non-face skin biopsies (Blenkinsopp, Clayton & Haffenden, 1978). T h e pattern of IgM and C3 that we see in PL is characteristic because in contrast to diseases such as lupus erythemaiosus IgM is the only immunogiobulin seen. Hayashi (.i^Tj) detected IgM and C3 both in dermal vessels and along the dermal-epidermal junction in his two patients with PL acuta. Departments of Dermatology and Histopathology, St Mary's Hospital,

ROGER CLAYTON GERALD HAI-FENDEN

Praed Street, London W2

237

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Correspondence

I AND 2. Granular C3 (Fig. i) and granular IgM (i-'ig. 2). in derma! papillary vessels and along the dermal epidermal junction from an oaily lesion of pityriasis lichenoides chronica.

Correspondence

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REFERENCES BLENKINSOPP, W.K., CLAYTON, R.J. & HAFFENDEN, G . (1978) Immunoglobulin and complement in normal

skin. Journal of Cutaneous Pathology, 31, 1143. CLAYTON, R.J., HAFFENDEN, G., DU VIVIER, A., BURTON, J. & MOWBRAY, J. (1977) Pityriasis lichenoides

—an immune complex disease. British Journal of Dermatology, 97, 629. HAYASHI, T . (1977) Pityriasis lichenoides varioHformis acuta: immunopathologic study. Journal of Dermatology, 69, 477-