Summary Forty patients with perioral dermatitis were assessed with particular reference to factors which might be incriminated in the aetiology of this condition. Many previously implicated features could not, in fact, be substantiated. We believe that perioral dermatitis is a distinct entity but that the abuse of topical corticosteroids aggravates the disease.

Three patients who developed a psoriasiform skin eruption following oral practolol administration are described with particular attention to the cutaneous histological changes. Although the clinical picture resembled psoriasis, the histological one did not, resembling rather that seen in a drug eruption. The possibility of an early lymphoma could not be excluded on purely histological grounds.

A case is described in which the initial clinical and histological features were suggestive of rosacea. Subsequent progress revealed the diagnosis to be chronic lymphatic leukemia. The initial biopsy specimens were reviewed and small but definite quantities of follicular mucinosis were noted after appropriate staining. If this had been noted earlier the diagnosis would have been made more rapidly. This case demonstrates the importance of detecting follicular mucinosis. We are not aware of follicular mucinosis having been described in association with chronic lymphatic leukemia previously. It is also rare for leukemias other than the monocytic type to present with cutaneous lesions, though skin lesions may occur in established cases.

Fourteen patients with clinical and histological evidence of mycosis fungoides have undergone a series of immunological tests. Significant findings include the presence of low numbers of E and EAC rosette-forming cells in the peripheral circulation of the mycosis fungoides patients. Elevated levels of IgE were seen in five of the mycosis fungoides patients, and the mean IgE level was significantly higher than in the control series. Possible explanations of these findings are considered.

SUMMARY Six patients with persistent nodular scabies are described. Initially the diagnosis was in doubt, and thus a lesion was biopsied in each case. The histology bore a striking resemblance to that of malignant lymphoid neoplasm in five cases. In the absence of a clinical diagnosis it was reported as such by experienced skin histopathologists. In the remaining case an accrues was seen histologically, but the type and extent of the dermal infiltrate suggested a concomitant adverse drug reaction. We feel that these histological appearances may be misleading and that even with accurate clinical details the true diagnosis may be made only on the subsequent progress of the patient.