ICHD criteria
The ICHD diagnostic criteria are:
Headache that, within 3 days of onset, fulfils criteria 2-4
Headache is present daily, and is unremitting, for > 3 months
At least two of the following pain characteristics:
bilateral location
pressing/tightening (non-pulsating) quality
mild or moderate intensity
not aggravated by routine physical activity such as walking or climbing
Both of the following:
no more than one of photophobia, phonophobia or mild nausea
neither moderate or severe nausea nor vomiting
Not attributed to another disorderNotes:

Headache may be unremitting from the moment of onset or very rapidly build up to continuous and unremitting pain. Such onset or rapid development must be clearly recalled and unambiguously described by the patient. Otherwise it is coded as 2.3 chronic tension-type headache. History and physical and neurological examinations do not suggest any of the disorders listed in groups 5-12 (including 8.2 medication overuse headaches and its subforms), or history and/or physical and/or neurological examinations do suggest such disorder but it is ruled out by appropriate investigations, or such disorder is present but headache does not occur for the first time in close temporal relation to the disorder. Criteria revision
Although the original Silberstein–Lipton criteria and the original description by Vanast make no suggestion for the exclusion of migrainous features in NDPH, the current ICHD criteria exclude patients with migrainous features. When migraine features are present, classification thus becomes problematic. It has been reported that migraine symptoms may be present in over 50% of NDPH patients. The current criteria definition thus excludes more than half of patients with new onset of daily headache.
There may or may not be a lump in the breast, and there may be redness, oozing and crusting, and a sore that does not heal.The symptoms usually affect the nipple and then spread to the areola and then the breast. It is common for the symptoms to wax and wane. Most women do not visit the doctor because they assume Pagets disease to be minor contact dermatitis or eczema. A lump or skin irritation that does not seem to heal for over a month indicates that attention by a specialist is needed. Pathophysiology
Pagets disease of the breast is characterised by Paget cells. Paget cells are large cells with clear cytoplasm (clear halo) and eccentric, hyperchromic nuclei found throughout the epidermis.There is some controversy as to whether these cells arise from the ductal system of the breast, or whether these cells are a result of in situ malignant transformation.According to the migratory theory, ductal carcinoma in situ cells migrate into the lactiferous sinuses and the nipple skin. Cancer cells disrupt the normal epithelial barrier and extracellular fluid accumulates on the surface of the skin, resulting in the crusting of the areola skin. Diagnosis
Recommended tests are a mammogram and a biopsy to confirm the diagnosis, and cytopathology may also be helpful. Pagets disease is difficult to diagnose due to its resemblance to dermatitis and eczema; even in patients after ductal carcinoma in situ surgery. Eczema tends to affect the areola first, and then the nipple, whereas Pagets spreads from the nipple.