The bridge of the nose, ear, occiput and malleolus do not have (adipose) subcutaneous tissue and stage 3 ulcers can be shallow. In contrast, areas of significant adiposity can develop extremely deep stage 3 pressure ulcers. Bone/tendon is not visible or directly palpable. Stage IV: Full thickness tissue loss with exposed bone, tendon or muscle. Slough or eschar may be present on some parts of the wound bed. Often include undermining and tunneling. The depth of a stage 4 pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput and malleolus do not have (adipose) subcutaneous tissue and these ulcers can be shallow. Stage 4 ulcers can extend into muscle and/or supporting structures (e.g., fascia, tendon or joint capsule) making osteomyelitis likely to occur. Exposed bone/tendon is visible or directly palpable. In 2012, the National Pressure Injury Advisory Panel stated that pressure ulcers with exposed cartilage are also classified as a stage 4. Unstageable: Full thickness tissue loss in which actual depth of the ulcer is completely obscured by slough (yellow, tan, gray, green or brown) and/or eschar (tan, brown or black) in the wound bed. Until enough slough and/or eschar is removed to expose the base of the wound, the true depth, and therefore stage, cannot be determined. Stable (dry, adherent, intact without erythema or fluctuance) eschar on the heels is normally protective and should not be removed.
Fixed drug reactions,  are common and so named because they recur at the same site with each exposure to a particular medication. Medications inducing fixed drug eruptions are usually those taken intermittently. Signs and symptoms
A painful and itchy reddish/purple patch of skin that occurs in the same location with repeated exposures to the culprit drug is the classic presentation of a fixed drug reaction. The lips, genitals, and hands are often involved. Cause
Medications that are commonly implicated as a cause of fixed drug eruptions include the following:

Cetirizine
Ciprofloxacin
Clarithromycin
Cotrimoxazole
Doxycycline
Fluconazole
NSAIDs (e.g., ibuprofen, etoricoxib, naproxen)
Phenytoin
Pseudoephedrine
Trimethoprim

See also
Drug eruption
List of cutaneous conditions
List of human leukocyte antigen alleles associated with cutaneous conditions
Stevens–Johnson syndrome

References


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